29
Equipment Categories
$.50/SF
Avg Savings with Optimized PM
2×
Equipment Life Extension
30%
Lower Maintenance Costs
Smarter Preventative MaintenanceGo Beyond General Best Practices
This free guide outlines industry best practices for HVAC preventative maintenance — a solid starting point for moving any program from reactive to planned.
But generic maintenance only gets you so far. Standard schedules cover the basics — filter changes, belt inspections, lubrication intervals — but can't account for the engineering differences between, say, a Trane chiller and a Carrier chiller. Manufacturer-specific PMs are built around how your equipment is actually designed to perform, helping you catch issues earlier, maintain warranty compliance, and maximize asset lifespan.
Until recently, extracting PMs from O&M manuals was too tedious for most teams to attempt. Now, Moat uses AI to deliver manufacturer-specific PMs, alerts, and dashboards — closing the gap between generic schedules and optimized maintenance. Without this precision, facilities typically overspend on unnecessary maintenance or underspend and allow premature equipment failure. Moat solves both problems through AI-powered technologies:
Manufacturer-Specific Guidelines
Moat goes beyond generic intervals, incorporating OEM-recommended preventative maintenance schedules tailored to your exact equipment makes and models.
Automated Scheduling
Moat automatically generates and manages maintenance schedules across all of your HVAC and related systems — no more manual tracking or missed service intervals.
Dashboards & Visibility
Get a real-time view of your entire maintenance program through intuitive dashboards — track compliance, upcoming tasks, and equipment health all in one place.
End-to-End Automation
From task assignment to completion tracking and documentation, Moat automates the full preventative maintenance workflow so nothing falls through the cracks.
Ready to stop guessing and start optimizing? Moat gives you the platform to manage every aspect of your preventative maintenance program — precisely, automatically, and at scale.
Purpose & Scope
This guide establishes general HVAC inspection and maintenance requirements to preserve a system's ability to achieve acceptable thermal comfort, energy efficiency, and indoor air quality in commercial buildings.
This guide applies to:
- New and existing commercial buildings
- Governmental and educational facilities
- Healthcare and hospitality facilities
- Institutional buildings
- Office buildings and places of assembly
- Restaurants and retail/wholesale businesses
- HVAC equipment primarily for industrial, manufacturing, or commercial processes
| Maintenance Level | Annual Cost ($/sq ft) | Equipment Life Impact | Energy Impact |
|---|---|---|---|
| Reactive (Run-to-Failure) | $2.50 – $3.50 | 50–60% of design life | 15–30% higher energy use |
| Preventive (This Standard) | $1.75 – $2.25 | 80–100% of design life | 5–10% higher energy use |
| Predictive/Optimized | $1.00 – $1.75 | 100–120% of design life | Near design efficiency |
PM Maturity Model
Where does your program stand today?
Reactive
Limited PM
No formal PM program. Most breaks are a surprise.
- No formal PM program
- Unplanned downtime & emergency repairs
- Shortened asset life
- No maintenance history
Planned
Generic PM
Your team has a baseline and is completing scheduled maintenance.
- Scheduled maintenance in place
- Asset-type checklists
- Reduced surprises
- Team accountability
Optimized
Manufacturer-Specific PM
Mobile-friendly PM tasks and frequencies automated directly from O&Ms using AI.
- Longer asset life & valid warranties
- Lower capital costs
- O&M-driven automation
- Mobile-friendly, manufacturer-specific PM
Reactive
Limited PM
No formal PM program. Most breaks are a surprise.
- No formal PM program
- Unplanned downtime & emergency repairs
- Shortened asset life
- No maintenance history
Planned
Generic PM
Your team has a baseline and is completing scheduled maintenance.
- Scheduled maintenance in place
- Asset-type checklists
- Reduced surprises
- Team accountability
Optimized
Manufacturer-Specific PM
Mobile-friendly PM tasks and frequencies automated directly from O&Ms using AI.
- Longer asset life & valid warranties
- Lower capital costs
- O&M-driven automation
- Mobile-friendly, manufacturer-specific PM
1. Implementation Framework
1.1 Responsible Parties
The building owner is responsible for meeting the requirements of this standard. The owner may designate other parties who shall be authorized and contractually obligated to fulfill the owner's responsibility.
1.2 Core Principles
Preventive Approach
Regular inspection and maintenance prevents system degradation and maintains design performance levels.
Documentation
All maintenance activities, findings, and corrective actions must be documented for trending and analysis.
Continuous Improvement
Maintenance programs should evolve based on actual equipment condition and performance data.
Energy Efficiency
Proper maintenance ensures systems operate at design efficiency levels, minimizing energy waste.
Indoor Air Quality
Regular maintenance prevents biological growth and maintains proper ventilation for occupant health.
Thermal Comfort
Maintained systems consistently deliver designed heating and cooling capacities for occupant comfort.
2. Equipment Lifespan by Maintenance Level
How long your HVAC assets actually last depends entirely on how you maintain them. The following reference shows estimated service life for all 29 equipment categories across three maintenance maturity levels — from reactive firefighting to optimized, manufacturer-specific programs.
Equipment Service Life Reference
Estimated Equipment Lifespan by Maintenance Level
How long your HVAC assets actually last depends on how you maintain them. These estimates show the impact of reactive, planned, and optimized PM programs on service life across all 29 equipment categories.
Lifespans shown in years
❄️
Chillers
3 Types| Sec. | Equipment | Limited PM / Reactive | Generic PM / Planned | Manufacturer-Specific PM / Optimized |
|---|---|---|---|---|
| 3.1.1 | Chillers – Water-Cooled | 12–15 | 20–25 | 28–35 |
| 3.1.2 | Chillers – Air-Cooled | 10–12 | 16–20 | 22–28 |
| 3.1.3 | Chillers – Absorption | 12–15 | 20–25 | 28–35 |
🌊
Cooling Support Equipment
3 Types| Sec. | Equipment | Limited PM / Reactive | Generic PM / Planned | Manufacturer-Specific PM / Optimized |
|---|---|---|---|---|
| 3.2.1 | Cooling Towers & Evaporative-Cooled Devices | 10–12 | 16–20 | 22–28 |
| 3.2.2 | Condensing Units | 8–10 | 12–15 | 17–22 |
| 3.2.3 | Evaporative Coolers | 8–10 | 12–15 | 17–20 |
🔥
Heating Equipment
3 Types| Sec. | Equipment | Limited PM / Reactive | Generic PM / Planned | Manufacturer-Specific PM / Optimized |
|---|---|---|---|---|
| 3.3.1 | Boilers | 12–15 | 20–25 | 28–35 |
| 3.3.2 | Furnaces – Combustion Unit Heaters | 10–13 | 16–20 | 22–28 |
| 3.3.3 | Unit Heaters – Gas Radiant | 9–11 | 14–18 | 20–25 |
💨
Air Handling & Distribution
6 Types| Sec. | Equipment | Limited PM / Reactive | Generic PM / Planned | Manufacturer-Specific PM / Optimized |
|---|---|---|---|---|
| 3.4.1 | Air Handlers | 12–15 | 20–25 | 28–35 |
| 3.4.2 | Rooftop Units | 8–10 | 12–15 | 17–22 |
| 3.4.3 | PTAC / PTHP | 7–9 | 12–15 | 16–20 |
| 3.4.4 | Indoor Section Duct-Free Splits | 8–10 | 12–15 | 17–20 |
| 3.4.5 | Fan Coils – Hot-Water & Steam Unit Heaters | 10–12 | 16–20 | 22–28 |
| 3.4.6 | Air Distribution Systems | 18–22 | 25–30 | 33–40 |
⚙️
Fans & Pumps
4 Types| Sec. | Equipment | Limited PM / Reactive | Generic PM / Planned | Manufacturer-Specific PM / Optimized |
|---|---|---|---|---|
| 3.5.1 | Fans – Centrifugal | 12–15 | 20–25 | 28–35 |
| 3.5.2 | Fans (Exhaust, Supply, Transfer, Return) | 10–12 | 16–20 | 22–28 |
| 3.5.3 | Pumps | 10–12 | 16–20 | 22–28 |
| 3.5.4 | Pumps – Boiler Fuel Oil | 10–12 | 16–20 | 22–28 |
🔧
Water & Steam Systems
3 Types| Sec. | Equipment | Limited PM / Reactive | Generic PM / Planned | Manufacturer-Specific PM / Optimized |
|---|---|---|---|---|
| 3.6.1 | HVAC Water Distribution Systems | 18–22 | 25–30 | 33–40 |
| 3.6.2 | Steam Distribution Systems | 18–22 | 25–30 | 33–40 |
| 3.6.3 | Coils and Radiators | 10–12 | 16–20 | 22–28 |
🏛️
Specialized Systems
6 Types| Sec. | Equipment | Limited PM / Reactive | Generic PM / Planned | Manufacturer-Specific PM / Optimized |
|---|---|---|---|---|
| 3.7.1 | Economizers – Air-Side | 10–12 | 16–20 | 22–28 |
| 3.7.2 | Outdoor-Air Heat-Exchanging Systems | 10–12 | 16–20 | 22–28 |
| 3.7.3 | Dehumidification & Humidification Devices | 8–10 | 12–15 | 17–20 |
| 3.7.4 | Water-Source Heat Pumps | 10–12 | 16–20 | 22–28 |
| 3.7.5 | Control Systems | 8–10 | 12–15 | 17–22 |
| 3.7.6 | Terminal & Control Boxes (VAV, Fan-Powered, Bypass) | 10–12 | 16–20 | 22–28 |
⚡
Power Generation
1 Type| Sec. | Equipment | Limited PM / Reactive | Generic PM / Planned | Manufacturer-Specific PM / Optimized |
|---|---|---|---|---|
| 3.8.1 | Engines – Microturbines | 8–10 | 12–15 | 17–22 |
Limited PMs / Reactive — No formal PM; equipment runs to failure with emergency repairs only.
Generic PMs / Planned — Scheduled PM with generic checklists. This guide's baseline.
Manufacturer-Specific PMs / Optimized — OEM-specific PM, predictive analytics, condition monitoring.
Estimates informed by ASHRAE Handbook, manufacturer guidance, and industry benchmarks. Actual lifespans vary by climate, load, water quality, and operating hours.
3. Equipment-Specific Maintenance Requirements
The following tables provide minimum inspection and maintenance requirements for common HVAC equipment. All applicable tasks must be included in your maintenance plan.
How to Use These Tables
- Identify all equipment types in your facility from your equipment inventory
- Reference the corresponding table for each equipment type
- Include ALL listed inspection and maintenance tasks in your maintenance plan
- Use the minimum frequencies shown (may increase frequency based on conditions)
- Document all task completions and findings
3.1 Chillers
3.1.1 Chillers – Water-Cooled
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Compressor | Inspect gearbox for excessive wear | Clean, lubricate, verify proper operation | Quarterly |
| Compressor | Perform compressor vibration analysis | Record baseline and trend data; investigate anomalies | Quarterly |
| Compressor | Check compressor oil level/pressure on systems with measurement means | When outside recommended levels, find and record cause | Annually |
| Compressor | Perform compressor oil analysis (acid test/spectrographic) | Check for acid, moisture, metal particulates; replace oil if needed | Annually |
| Compressor | Check compressor crankcase/sump heater operation (if applicable) | Repair or replace as needed | Annually |
| Controls | Check control system and devices for improper operation | Clean, lubricate, verify proper operation | Semiannually |
| Controls | Test all safety controls (high/low pressure cutouts, oil pressure safety, freeze protection, flow switch) | Simulate fault conditions to verify proper operation | Annually |
| Controls | Calibrate and verify temperature and pressure sensors/transducers | Recalibrate or replace as needed | Annually |
| Controls | Review and download fault/alarm history logs from chiller controller | Investigate recurring faults; update firmware if applicable | Annually |
| Controls | Verify chiller staging and sequencing with BAS | Correct programming discrepancies | Annually |
| Documentation | Record and trend all operating data (pressures, temps, amps, approach temps) | Calculate condenser/evaporator approach temperatures; flag degradation trends | Every Visit |
| Electrical | Check variable-frequency drive | Clean housing, tighten connections, clean/replace air filter | Semiannually |
| Electrical | Measure and record voltage and amperage at full load | Compare against nameplate ratings; investigate deviations | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Electrical | Check motor contactor for pitting or damage | Clean and tighten electrical connections | Annually |
| Electrical | Perform megohm (insulation resistance) testing of compressor motor windings | Record results and trend over time; investigate degradation | Annually |
| Electrical | Perform thermographic (infrared) scan of electrical connections and switchgear | Identify and repair hot spots | Annually |
| Evaporator | Check for buildup, fouling, corrosion on heat exchange surfaces | Clean and restore as needed | Annually |
| Evaporator | Pull and inspect condenser tubes or heat exchanger passages | Clean, descale, and document condition | Annually |
| Evaporator | Perform eddy current testing of condenser and evaporator tubes | Identify tube wall thinning; plan replacements | Every 3–5 Years |
| Fluid System | Perform chemical testing of system water | Treat to ensure proper chemistry and freeze protection | Monthly |
| Fluid System | Check water flow rate and pressure differential across evaporator | Adjust balancing valve; document deviations from design GPM | Monthly |
| Fluid System | Check for proper fluid flow and leaks | Adjust flow, record leak locations | Annually |
| Mechanical | Check open drive couplings, bearings, seals for wear or alignment | Lubricate and align as needed | Annually |
| Mechanical | Assess field-serviceable bearings | Lubricate as necessary | Annually |
| Refrigerant | Check refrigerant system pressures/temperatures | When outside recommended levels, find and record cause | Annually |
| Refrigerant | Verify proper refrigerant charge (superheat/subcooling method) | Adjust charge as needed; record readings | Annually |
| Refrigerant | Perform dedicated refrigerant leak detection survey | Repair leaks; document per EPA requirements | Annually |
3.1.2 Chillers – Air-Cooled
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Compressor | Perform compressor vibration analysis | Record baseline and trend data; investigate anomalies | Semiannually |
| Compressor | Check compressor oil level/pressure on systems with measurement means | When outside recommended levels, find and record cause | Annually |
| Compressor | Perform compressor oil analysis (acid test/spectrographic) | Check for acid, moisture, metal particulates; replace oil if needed | Annually |
| Compressor | Check compressor crankcase/sump heater operation (if applicable) | Repair or replace as needed | Annually |
| Condenser | Check for fin damage and fouling on condenser coils | Clean and restore as needed | Semiannually |
| Condenser | Check condenser fan blade condition and housing | Clean and inspect for damage | Semiannually |
| Controls | Check control system and devices for improper operation | Clean, lubricate, verify proper operation | Semiannually |
| Controls | Test all safety controls (high/low pressure cutouts, oil pressure safety, freeze protection, flow switch) | Simulate fault conditions to verify proper operation | Annually |
| Controls | Calibrate and verify temperature and pressure sensors/transducers | Recalibrate or replace as needed | Annually |
| Controls | Review and download fault/alarm history logs from chiller controller | Investigate recurring faults; update firmware if applicable | Annually |
| Controls | Verify chiller staging and sequencing with BAS | Correct programming discrepancies | Annually |
| Documentation | Record and trend all operating data (pressures, temps, amps, approach temps) | Calculate condenser/evaporator approach temperatures; flag degradation trends | Every Visit |
| Electrical | Check variable-frequency drive | Clean housing, tighten connections, clean/replace air filter | Semiannually |
| Electrical | Measure and record voltage and amperage at full load | Compare against nameplate ratings; investigate deviations | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Electrical | Check motor contactor for pitting or damage | Clean and tighten electrical connections | Annually |
| Electrical | Perform megohm (insulation resistance) testing of compressor motor windings | Record results and trend over time; investigate degradation | Annually |
| Electrical | Perform thermographic (infrared) scan of electrical connections | Identify and repair hot spots | Annually |
| Evaporator | Check for buildup, fouling, corrosion on evaporator heat exchange surfaces | Clean and restore as needed | Annually |
| Evaporator | Pull and inspect evaporator tubes or heat exchanger passages | Clean, descale, and document condition | Annually |
| Evaporator | Perform eddy current testing of evaporator tubes | Identify tube wall thinning; plan replacements | Every 3–5 Years |
| Fluid System | Perform chemical testing of system water/glycol solution | Treat to ensure proper chemistry and freeze protection | Monthly |
| Fluid System | Check for proper fluid flow and leaks | Adjust flow, record leak locations | Annually |
| General | Inspect unit for proper clearances and airflow obstructions | Remove obstructions; document clearance deficiencies | Annually |
| Mechanical | Assess field-serviceable bearings | Lubricate as necessary | Annually |
| Refrigerant | Check refrigerant system pressures/temperatures | When outside recommended levels, find and record cause | Annually |
| Refrigerant | Verify proper refrigerant charge (superheat/subcooling method) | Adjust charge as needed; record readings | Annually |
| Refrigerant | Perform dedicated refrigerant leak detection survey | Repair leaks; document per EPA requirements | Annually |
| Refrigerant | Inspect expansion valves (TXV/EEV) for proper operation | Clean or replace as needed; verify superheat/subcooling | Annually |
| Refrigerant | Inspect filter driers and sight glass moisture indicators | Replace filter driers if moisture or acid detected | Annually |
3.1.3 Chillers – Absorption
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Combustion | Inspect burner assembly and combustion components (direct-fired units) | Clean and adjust combustion process; verify flame pattern | Semiannually |
| Controls | Check control system and devices for improper operation | Clean, lubricate, verify proper operation | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Evaporator | Check for buildup, fouling, corrosion on heat exchange surfaces | Clean and restore as needed | Annually |
| Evaporator | Eddy current test heat exchanger tubes (evaporator, absorber, condenser, generator) | Identify thinning or pitting; plug or replace tubes as needed | Every 3–5 Years |
| Fluid System | Perform chemical testing of system water and lithium bromide solution | Treat to ensure proper chemistry; adjust inhibitor concentrations | Monthly |
| Fluid System | Check crystallization risk — monitor lithium bromide concentration and temperature | Adjust concentration and temperature controls; prevent crystallization events | Monthly |
| Fluid System | Check vacuum integrity of the absorption cycle shell | Perform helium or nitrogen leak test; repair leaks; operate purge unit | Semiannually |
| Fluid System | Check for proper fluid flow and water-side pressure drops | Adjust flow, record anomalies | Annually |
| Mechanical | Check solution pump operation and purge system | Verify proper flow and purge pump operation; log purge activity | Monthly |
| Mechanical | Assess hermetic solution and refrigerant pumps for wear | Lubricate or replace as necessary per manufacturer specification | Annually |
| Refrigerant | Inspect solution and refrigerant circuits for leaks | Record location of identified leaks; repair as required | Annually |
| Safety | Verify safety devices and interlocks per manufacturer recommendations | Test, clean, and adjust | Annually |
3.2 Cooling Support Equipment
3.2.1 Cooling Towers and Evaporative-Cooled Devices
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Biological | Test for Legionella and other biological growth per water management plan | Shock treat if levels exceed thresholds; review water treatment program | Monthly |
| Controls | Check conductivity and other sensors | Clean and verify proper operation | Monthly |
| Controls | Check control system and devices for improper operation | Clean, lubricate, adjust | Semiannually |
| Electrical | Check variable-frequency drive | Clean housing, tighten connections, clean/replace air filter | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Electrical | Check motor contactor for pitting or damage | Clean and tighten electrical connections | Annually |
| Electrical | Inspect basin heater (if applicable) for proper operation | Test heater and thermostat; repair or replace as needed | Annually |
| Fluid System | Perform chemical testing of system water | Treat to ensure proper chemistry and freeze protection | Monthly |
| Fluid System | Check water system ultraviolet lamp | Clean and verify functioning | Quarterly |
| Fluid System | Check chemical injector device | Verify water treatment target levels | Quarterly |
| Fluid System | Check make-up water float valve and makeup water flow rate | Adjust float; verify makeup rate is not excessive (indicating leaks) | Quarterly |
| Fluid System | Check for proper fluid flow and leaks | Adjust flow, record leak locations | Annually |
| General | Check for fouling, corrosion, degradation, dirt in sump, wet decks, fill, nozzles, louvers | Clean and restore as needed | Quarterly |
| Mechanical | Inspect blowdown or drain valve | Clean and verify proper operation | Quarterly |
| Mechanical | Check cooling-tower-fan open drive couplings, bearings, seals | Lubricate and align as needed | Quarterly |
| Mechanical | Check fan-belt tension, wear, sheave alignment | Correct tension and alignment | Quarterly |
| Mechanical | If two-stage tower, verify proper operation at both flow rates | Clean and verify proper operation | Quarterly |
| Mechanical | Inspect pumps and associated electrical components | Clean and verify proper operation | Semiannually |
| Mechanical | Check fan blades and housing | Clean as needed | Annually |
| Mechanical | Assess field-serviceable bearings | Lubricate as necessary | Annually |
| Mechanical | Check for proper damper operation | Clean, lubricate, repair, replace, or adjust | Annually |
| Mechanical | Check cooling tower motors and pumps | Clean housing, tighten connections, clean strainers | Annually |
| Structural | Inspect tower structure, basin, casing, and fill for corrosion and mechanical damage | Repair or replace damaged fill, casing panels, or structural members | Annually |
3.2.2 Condensing Units
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Compressor | Check compressor oil level/pressure on systems with measurement means | When outside recommended levels, find and record cause | Annually |
| Compressor | Check compressor crankcase heater operation | Repair or replace heater as needed | Annually |
| Condenser | Check for fin damage and fouling on condenser coil surfaces | Clean and restore as needed | Semiannually |
| Condenser | Check condenser fan blades and housing | Clean and inspect for damage or imbalance | Semiannually |
| Controls | Check control system and devices for improper operation | Clean, lubricate, adjust | Semiannually |
| Controls | Test high-pressure and low-pressure safety cutouts | Verify trip points; replace failed safety devices | Annually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Electrical | Check motor contactor for pitting or damage | Clean and tighten electrical connections | Annually |
| Electrical | Measure and record compressor motor amperage at full load | Compare to nameplate; investigate deviations | Annually |
| General | Inspect unit for proper clearances and obstructions to condenser airflow | Remove obstructions; document deficiencies | Annually |
| Mechanical | Assess field-serviceable bearings on fan motors | Lubricate as necessary | Annually |
| Refrigerant | Check refrigerant system pressures and temperatures | When outside recommended levels, find and record cause | Annually |
| Refrigerant | Perform dedicated refrigerant leak detection survey | Repair leaks; document per EPA requirements | Annually |
| Refrigerant | Inspect filter driers and sight glass moisture indicators | Replace filter driers if moisture or acid detected | Annually |
| Structural | Check integrity of all panels and fasteners | Replace fasteners as needed | Annually |
3.2.3 Evaporative Coolers
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Documentation | Fill out maintenance checklist | Complete documentation | Annually |
| Electrical | Visually inspect wiring for damage or loose connections; tighten loose connections | Tighten connections | Annually |
| Fluid System | Perform chemical testing of sump water and check water treatment | Treat water; verify bleed-off rate; prevent scale and biological growth | Monthly |
| Fluid System | Clean and adjust float | Adjust float for proper water level | Annually |
| General | Check with operating/area personnel for deficiencies | Document and report findings | Annually |
| General | Check unit for proper operation, noise and vibration | Document findings | Annually |
| General | Clean evaporation louver panels | Remove scale, algae and debris | Annually |
| General | Clean sump and pump intake | Remove debris and biological growth | Annually |
| General | Check interior surfaces and components for loose paint/lime deposits | Document and clean as needed | Annually |
| General | Check/clean and adjust nozzles | Clean and adjust flow pattern | Annually |
| General | Remove, clean and reinstall evaporative pads | Clean pads thoroughly; replace if deteriorated | Annually |
| General | Start unit and check for proper operation | Verify all systems function correctly after maintenance | Annually |
| General | Remove debris from surrounding area | Maintain housekeeping | Annually |
| Lubrication | Lubricate rotary and fan bearings and motor | Lubricate as required | Annually |
| Mechanical | Check belt(s) for excessive wear and deterioration | Inspect and document condition | Annually |
| Mechanical | Inspect water distribution header and lateral pipes for scale or blockage | Flush and clean distribution system; verify even water distribution | Annually |
3.3 Heating Equipment
3.3.1 Boilers
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Combustion | For fuel oil systems, inspect fuel filter | Clean and verify proper operation | Monthly |
| Combustion | For fuel oil systems, check fuel pump | Clean and verify proper operation | Quarterly |
| Combustion | Check for leakage of fuel supply, heat transfer fluid, flue gas | Record location of identified leaks | Quarterly |
| Combustion | For natural gas systems, check gas pressure, valve operation, combustion fan | Clean and verify proper operation | Quarterly |
| Combustion | Perform flue gas analysis (O2, CO2, CO, stack temperature) | Adjust air/fuel ratio to achieve optimal combustion efficiency | Quarterly |
| Combustion | Check combustion chamber, burner, flue for deterioration, moisture, combustion products | Clean and adjust combustion process | Annually |
| Combustion | Inspect refractory for damage or wear | Clean combustion-side, record refractory damage | Annually |
| Combustion | Observe burner flame at high load for correct clearance | Clean and adjust | Annually |
| Controls | Check control system and devices for improper operation | Clean, lubricate, verify proper operation | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Electrical | Check motor contactor for pitting or damage | Clean and tighten electrical connections | Annually |
| Heat Exchange | Check for buildup, fouling, corrosion on heat-exchange surfaces | Clean and restore as needed | Annually |
| Fluid System | Perform chemical testing of system water | Verify water treatment target levels | Monthly |
| Fluid System | Inspect and test condensate neutralizer (condensing boilers) | Replace neutralizer media as needed; verify pH of condensate discharge | Annually |
| Mechanical | Inspect blowdown or drain valve | Clean and verify proper operation | Quarterly |
| Mechanical | Check dampers for condition, setting, operation | Adjust and lubricate as necessary | Annually |
| Safety | Test low-water cutoff operation | Slow-drain test or probe test; clean probe/float assembly; replace if failed | Monthly |
| Safety | Test pressure relief valve operation | Manual lift test; replace valve if failed or leaking after test | Semiannually |
| Safety | Verify proper operation of safety devices per manufacturer recommendations | Clean, lubricate, adjust | Annually |
| Structural | Inspect flue venting and breeching for deterioration, corrosion, and proper draft | Clean flue passages; repair or replace deteriorated sections | Annually |
3.3.2 Furnaces – Combustion Unit Heaters
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Combustion | Check fuel supply pressure and valve operation | Clean and verify proper operation; record anomalies | Quarterly |
| Combustion | Inspect fuel system for leaks at connections and valves | Record location of leaks; repair as required | Quarterly |
| Combustion | Perform flue gas analysis (O2, CO2, CO, stack temperature) | Adjust air/fuel ratio; document combustion efficiency | Semiannually |
| Combustion | Check combustion chamber, burner, and flue for deterioration, moisture, or combustion products | Clean and adjust combustion process | Annually |
| Combustion | Observe burner flame pattern and adjust for correct combustion | Clean burner components; adjust air/fuel ratio | Annually |
| Combustion | Inspect induced draft/forced draft fan assembly for wear and debris | Clean blades; lubricate bearings; verify proper airflow | Annually |
| Controls | Check control system and devices for improper operation | Clean, lubricate, verify proper operation | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Heat Exchange | Inspect heat exchanger surfaces for cracks, leaks, or corrosion | Record damage locations; replace heat exchanger if compromised | Annually |
| General | Check filter for particulate accumulation | Clean or replace as needed | Quarterly |
| Mechanical | Check blower fan, motor, and belt (if applicable) for wear | Lubricate bearings; correct belt tension and alignment | Annually |
| Safety | Verify proper operation of safety devices (limit switch, pressure switches, flame sensor) | Test, clean, and adjust; replace failed devices | Annually |
| Safety | Perform carbon monoxide (CO) testing near unit during operation | Investigate and repair source if CO levels are elevated | Annually |
| Structural | Check flue and venting for proper draft, blockage, and deterioration | Clean flue; repair or replace deteriorated sections | Annually |
3.3.3 Unit Heaters – Gas Radiant
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Combustion | Check fuel supply pressure and inspect for gas leaks | Use approved leak detection solution or instrument; repair leaks immediately | Quarterly |
| Combustion | Inspect fuel system for leaks | Document findings | Annually |
| Controls | Inspect, clean and adjust control valves and thermo sensing bulbs on gas burners | Clean and adjust | Annually |
| Controls | Check for proper operation of burner controls; check and adjust thermostat | Clean, lubricate, adjust | Annually |
| Documentation | Fill out maintenance checklist and report deficiencies | Complete documentation | Annually |
| Electrical | Check electrical wiring to blower motor | Tighten connections; inspect insulation | Annually |
| General | Check with operating/area personnel for deficiencies | Document and report findings | Annually |
| General | Inspect radiant tubes/emitter surfaces for cracks, discoloration, or blockage | Clean exterior surfaces; replace cracked or damaged emitters | Annually |
| General | Check unit heater operation through complete cycle or up to 10 minutes | Observe and document performance | Annually |
| General | Clean area around unit heater | Remove debris, maintain housekeeping | Annually |
| Mechanical | Check fan and motor for vibration and noise; lubricate bearings | Lubricate bearings | Annually |
| Safety | Perform CO testing at unit during operation | Investigate and address elevated CO readings | Annually |
| Structural | Check condition of flue pipe, damper and stack | Inspect and document condition | Annually |
3.4 Air Handling & Distribution
3.4.1 Air Handlers
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Airflow | Verify outdoor air damper opens to minimum position and economizer operates correctly | Adjust actuator and control sequence; repair damper linkages | Quarterly |
| Airflow | Measure and record supply, return, and outdoor airflow rates | Adjust dampers or fan speed to restore design airflow; document deviations | Semiannually |
| Biological | Check drain pan, drain line, coil for biological growth | Clean and verify proper operation | Quarterly |
| Biological | Inspect for moisture carryover beyond drain pan from cooling coils | Clean as needed | Annually |
| Controls | Check control system and devices for improper operation | Clean, lubricate, adjust | Semiannually |
| Electrical | Check variable-frequency drive for proper operation | Clean housing, tighten connections, clean/replace air filter | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Electrical | Check motor contactor for pitting or damage | Clean and tighten electrical connections | Annually |
| Electrical | Measure and record fan motor amperage and compare to nameplate | Investigate motor overloading; check for restriction or mechanical issues | Annually |
| Fluid System | Check P-trap | Prime as needed | Quarterly |
| Fluid System | Check condensate pump | Clean and verify proper operation | Annually |
| General | Check for particulate accumulation on filters | Clean or replace as needed | Quarterly |
| General | Check ultraviolet lamp | Clean and verify functioning | Quarterly |
| General | Check air-filter fit and housing seal integrity | Clean and verify proper fit/finish | Annually |
| General | Inspect AHU casing interior for corrosion, condensation, and biological growth | Clean and treat surfaces; repair casing leaks and insulation damage | Annually |
| Heat Exchange | Check for damage or leaks on heat exchanger surfaces | Record location of identified leaks | Semiannually |
| Heat Exchange | Check for fin damage and fouling on heat exchanger surfaces | Clean and restore as needed | Annually |
| Mechanical | Check steam system traps, pumps, strainers, controls | Clean and verify proper operation | Semiannually |
| Mechanical | Check fan-belt tension, wear, and sheave alignment | Correct tension and alignment | Semiannually |
| Mechanical | Check fan blades and housing | Clean as needed | Annually |
| Mechanical | Assess field-serviceable bearings | Lubricate as necessary | Annually |
| Mechanical | Check dampers for condition, setting, operation | Adjust and lubricate as necessary | Annually |
| Refrigerant | Check refrigerant system temperatures | When outside recommended levels, find and record cause | Annually |
| Structural | Check integrity of all panels on equipment | Replace fasteners as needed | Annually |
| Structural | Inspect exposed ductwork insulation and vapor barrier integrity | Record location of damage | Annually |
3.4.2 Rooftop Units
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Biological | Check drain pan, drain line, coil for biological growth | Clean and verify proper operation | Quarterly |
| Biological | Inspect for moisture carryover beyond drain pan | Clean as needed | Annually |
| Biological | Inspect insulation and areas of moisture accumulation for biological growth | Clean as needed | Annually |
| Combustion | Check combustion chamber, burner, flue for deterioration, leaks, moisture | Clean and adjust combustion process, record leak locations | Annually |
| Combustion | Perform flue gas analysis for gas-fired RTUs | Adjust air/fuel ratio; verify combustion efficiency | Annually |
| Compressor | Check compressor oil levels/pressure on systems with measurement means | When outside recommended levels, find and record cause | Annually |
| Condenser | Check for fin damage and fouling on outdoor heat exchanger surfaces | Clean and restore as needed | Semiannually |
| Condenser | Check for damage or leaks on outdoor heat-exchanger surfaces | Check for damage or leaks | Annually |
| Controls | Check control system and devices for improper operation | Clean, lubricate, adjust | Semiannually |
| Controls | Check low ambient head pressure control sequence | Clean and adjust components or modify software | Annually |
| Electrical | Check variable-frequency drive | Clean housing, tighten connections, clean/replace air filter | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Electrical | Check motor contactor for pitting or damage | Clean and tighten electrical connections | Annually |
| Electrical | Measure and record compressor and fan motor amperage at full load | Compare to nameplate; investigate deviations | Annually |
| Fluid System | Check P-trap | Prime as needed | Quarterly |
| General | Check for particulate accumulation on filters | Clean or replace as needed | Quarterly |
| General | Check ultraviolet lamp | Clean and verify functioning | Quarterly |
| General | Check air-filter fit and housing seal integrity | Clean and verify proper fit/finish | Annually |
| Heat Exchange | Check for fin damage and fouling on indoor heat exchanger surfaces | Clean and restore as needed | Semiannually |
| Heat Exchange | Check for damage or leaks on indoor heat-exchanger surfaces | Clean and restore, record leak locations | Annually |
| Heat Exchange | Check for damage or leaks on gas heat section heat-exchanger surfaces | Clean as needed, record leak locations | Annually |
| Mechanical | Check steam system traps, pumps, controls | Clean and verify proper operation | Semiannually |
| Mechanical | Check fan-belt tension, wear, sheave alignment | Correct tension and alignment | Semiannually |
| Mechanical | Check fan blades and housing | Clean as needed | Annually |
| Mechanical | Check fan drive for wear or alignment problems | Adjust and lubricate as necessary | Annually |
| Mechanical | Assess field-serviceable bearings | Lubricate as necessary | Annually |
| Mechanical | Check dampers for condition, setting, operation | Adjust and lubricate as necessary | Annually |
| Refrigerant | Check refrigerant system pressures/temperatures during operation | When outside recommended levels, find and record cause | Quarterly |
| Refrigerant | Check refrigerant system temperatures | When outside recommended levels, find and record cause | Annually |
| Refrigerant | Perform dedicated refrigerant leak detection survey | Repair leaks; document per EPA requirements | Annually |
| Structural | Check integrity of all panels and curbs | Replace fasteners as needed | Annually |
| Structural | Inspect exposed ductwork and external piping insulation and vapor barrier | Record location of damage | Annually |
| Structural | Inspect roof curb, flashing, and unit base for water infiltration | Re-seal curb; repair flashing; document moisture intrusion | Annually |
3.4.3 Package Terminal Air Conditioners/Heat Pumps (PTAC/PTHP)
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Condenser | Check outdoor condenser coil for fouling and fin damage | Clean and restore fins as needed | Semiannually |
| Controls | Check control system, thermostat, and controls for proper operation | Clean, calibrate, and adjust | Annually |
| Electrical | Check electrical connections and wiring | Tighten connections; inspect insulation | Annually |
| Electrical | Check electric resistance heating elements and limit switches (if equipped) | Test continuity; verify limit switch trip point; replace failed elements | Annually |
| Evaporator | Check indoor evaporator coil for fouling and biological growth | Clean coil surfaces; disinfect as needed | Semiannually |
| Fluid System | Check drain pan and condensate drainage for blockage or biological growth | Clean drain pan and drain path; verify proper drainage | Quarterly |
| General | Check indoor air filter for particulate accumulation | Clean or replace filter as needed | Quarterly |
| Mechanical | Check fan blades and housing (indoor and outdoor sections) | Clean and inspect for damage | Annually |
| Mechanical | Check outdoor fresh air ventilation damper for proper operation | Clean, lubricate, adjust | Annually |
| Refrigerant | Check refrigerant system temperatures and pressures | When outside recommended levels, find and record cause | Annually |
| Refrigerant | Check reversing valve operation in heat pump mode (PTHP only) | Verify proper switching between heating and cooling; replace if stuck | Annually |
| Structural | Inspect unit sleeve and wall sleeve for corrosion and air leakage | Seal gaps; treat corrosion; document condition | Annually |
3.4.4 Indoor Section Duct-Free Splits
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Biological | Check indoor coil surfaces for fouling or biological growth | Clean coil surfaces; disinfect as needed | Semiannually |
| Controls | Check control system and remote sensors/thermostats for proper operation | Clean, calibrate, adjust | Annually |
| Electrical | Check electrical connections and wiring at indoor unit | Tighten connections; inspect insulation | Annually |
| Fluid System | Check drain pan and condensate drain line for biological growth and blockage | Clean and verify proper drainage | Quarterly |
| General | Check indoor unit air filter for particulate accumulation | Clean or replace filter as needed | Quarterly |
| General | Verify unit delivers adequate heating or cooling at design conditions | Document performance deviations; adjust as needed | Annually |
| Mechanical | Check indoor unit fan and housing for dirt accumulation | Clean fan blades and housing | Semiannually |
| Mechanical | Check and clean louver, vane motor, and airflow direction components | Lubricate vane motor; replace if not responding to control signal | Annually |
| Refrigerant | Check refrigerant line set connections, fittings, and service valve caps | Tighten caps; check for leak signs (oil staining); document | Semiannually |
| Refrigerant | Check refrigerant system temperatures and pressures | When outside recommended levels, find and record cause | Annually |
| Refrigerant | Perform refrigerant leak detection survey at indoor and outdoor units | Repair leaks; document per EPA requirements; recharge as needed | Annually |
| Structural | Check refrigerant line connections and insulation for integrity | Record damage locations; repair insulation as needed | Annually |
3.4.5 Fan Coils – Hot-Water and Steam Unit Heaters
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Biological | Check drain pan and condensate drain for biological growth and blockage (cooling applications) | Clean and verify proper drainage | Quarterly |
| Controls | Check control valve and actuator for proper operation and response to thermostat | Clean, lubricate, adjust; repair or replace as needed | Semiannually |
| Electrical | Check electrical wiring and connections | Tighten connections; inspect insulation | Annually |
| Fluid System | Check water pressure differential and flow rate through coil | Verify flow meets design; clean strainer; adjust balancing valve | Semiannually |
| Fluid System | Check piping connections and coil for leaks | Record location of leaks; repair as required | Annually |
| Fluid System | Inspect and bleed air from coil and piping | Open manual air vent; verify water flow restored; close vent when water runs clear | Annually |
| General | Check filter for particulate accumulation | Clean or replace as needed | Quarterly |
| General | Verify unit delivers adequate heating or cooling at design conditions | Document performance deviations; adjust controls as needed | Annually |
| General | Check and clean unit cabinet, grilles, and return air opening | Remove dust buildup; ensure grilles are unobstructed | Annually |
| Heat Exchange | Check coil surfaces for fin damage, fouling, or corrosion | Clean and restore fins as needed | Annually |
| Lubrication | Lubricate fan motor bearings | Lubricate per manufacturer specification | Annually |
| Mechanical | Check fan blade and housing for dirt accumulation and noise | Clean fan blades and housing | Annually |
| Mechanical | For steam unit heaters, check steam trap and strainer for proper operation | Clean strainer; verify trap function; replace failed traps | Annually |
3.4.6 Air Distribution Systems
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Airflow | Inspect grilles, registers, and diffusers for dirt accumulation | Clean as needed to remove dirt buildup | Semiannually |
| Airflow | Spot-check supply and return airflow rates at representative zones | Adjust balancing dampers; document deviations from design | Semiannually |
| Biological | Inspect areas of moisture accumulation for biological growth | If present, clean | Annually |
| Biological | Inspect internally lined ductwork from moisture sources (up to 20 ft) for water damage | Determine and record source of moisture | Annually |
| Controls | Check control system and devices for improper operation | Clean, lubricate, repair, adjust | Semiannually |
| General | Verify smoke dampers and fire dampers are unobstructed and accessible | Coordinate with life safety inspection; document access issues | Annually |
| Mechanical | Check dampers for condition, setting, and operation | Clean, lubricate, repair, replace, or adjust | Semiannually |
| Structural | Inspect exposed ductwork for insulation and vapor barrier integrity | Record damage locations | Annually |
| Structural | Inspect accessible duct sections for leakage at seams, joints, and connections | Seal leaks with mastic or approved duct tape; document leakage locations | Annually |
3.5 Fans & Pumps
3.5.1 Fans – Centrifugal
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Airflow | Verify fan airflow output against design specifications | Adjust speed or damper positions; document deviations | Annually |
| Electrical | Check electrical wiring and connections; tighten loose connections | Tighten connections | Semiannually |
| Electrical | Measure fan motor amperage and compare to nameplate | Investigate overloading; check for airflow restrictions or mechanical drag | Semiannually |
| General | Clean fan and surrounding area | Remove debris, maintain housekeeping | Semiannually |
| Lubrication | Check motor and fan shaft bearings for noise, vibration, overheating | Lubricate bearings | Semiannually |
| Mechanical | Start and stop fan with local switch | Verify proper operation | Semiannually |
| Mechanical | Check belts for wear, tension, and alignment | Correct tension and alignment | Semiannually |
| Mechanical | Check blower intake dampers; lubricate (if applicable) | Lubricate pivot points and linkages | Semiannually |
| Mechanical | Inspect impeller/wheel for erosion, buildup, or imbalance | Clean wheel; rebalance or replace if excessive vibration persists | Annually |
| Structural | Check flexible duct connections and vibration isolators at fan inlet/outlet | Replace deteriorated flex connectors; verify isolation mounts are intact | Annually |
3.5.2 Fans (Exhaust, Supply, Transfer, Return)
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Airflow | Verify airflow meets design requirements | Adjust fan speed or dampers; document deviations from design | Annually |
| Electrical | Check electrical wiring and connections | Tighten connections; inspect insulation for damage | Semiannually |
| Electrical | Measure fan motor amperage and compare to nameplate rating | Investigate overloading; check for airflow restriction or mechanical drag | Semiannually |
| Electrical | Check variable-frequency drive for proper operation (if applicable) | Clean housing, tighten connections, clean/replace air filter | Annually |
| Electrical | Check motor contactor for pitting or damage | Clean and tighten electrical connections | Annually |
| Lubrication | Check motor and fan shaft bearings for noise, vibration, and overheating | Lubricate bearings per manufacturer specification | Semiannually |
| Mechanical | Start and stop fan with local switch; verify proper rotation direction | Correct wiring if rotation is reversed; document findings | Semiannually |
| Mechanical | Check belts for wear, tension, and alignment | Correct tension and alignment; replace worn belts | Semiannually |
| Mechanical | Check inlet and outlet dampers and louvers for proper operation | Lubricate pivot points and linkages; repair or replace as needed | Semiannually |
| Mechanical | Check fan blades and housing for debris accumulation and damage | Clean fan blades and housing; document damage | Annually |
| Structural | Inspect flexible duct connections and vibration isolation mounts | Replace deteriorated flex connectors; verify isolation mounts are secure | Annually |
3.5.3 Pumps
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Electrical | Measure pump motor amperage and compare to nameplate | Investigate deviations; check for cavitation, restriction, or mechanical issues | Quarterly |
| Electrical | Check variable-frequency drive for proper operation (if applicable) | Clean housing, tighten connections, clean/replace air filter | Semiannually |
| Electrical | Check motor contactor and control box for dirt and loose terminations | Clean and tighten electrical connections | Annually |
| Fluid System | Check for leaks at seals, flanges, and discharge piping | Inspect and document leaks; repair as required | Quarterly |
| Fluid System | Check suction strainer for debris accumulation | Clean strainer basket | Quarterly |
| Fluid System | Verify pump flow rate and pressure meet design requirements | Adjust balancing valve; document deviations from design | Annually |
| General | Check with operating/area personnel for deficiencies | Document and report findings | Quarterly |
| General | Inspect expansion joints and flexible connectors on pump piping | Replace deteriorated connectors; verify isolation is adequate | Annually |
| Lubrication | Lubricate pump and motor bearings as required | Lubricate per manufacturer specification | Semiannually |
| Mechanical | Check pump and motor operation for vibration, noise, and overheating | Document findings; investigate abnormal conditions | Quarterly |
| Mechanical | Check alignment and clearances of shaft and coupler | Realign as necessary; verify coupling condition | Semiannually |
| Mechanical | Check impeller and pump casing for wear or buildup | Clean impeller; document wear; replace as needed | Annually |
| Mechanical | Inspect mechanical seal or packing for excessive leakage | Adjust packing gland; replace mechanical seal if seal face is damaged | Annually |
3.5.4 Pumps – Boiler Fuel Oil
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Fluid System | Check for leaks on discharge piping and seals | Inspect and document leaks | Semiannually |
| Fluid System | Check fuel supply strainer/filter for sediment or biological growth | Clean or replace strainer; address water or biological contamination in tank | Semiannually |
| Fluid System | Verify pump discharge pressure against boiler burner requirements | Adjust pressure regulating valve; document pressure deviations | Semiannually |
| General | Check with operating/area personnel for deficiencies | Document and report findings | Semiannually |
| General | Clean pump, motor and surrounding area | Remove debris, maintain housekeeping | Semiannually |
| Lubrication | Lubricate pump and motor as required | Lubricate per manufacturer specification | Semiannually |
| Mechanical | Check pump and motor operation for vibration, noise, overheating | Document findings | Semiannually |
| Mechanical | Check alignment and clearances of shaft and coupler | Realign as necessary | Semiannually |
| Structural | Tighten or replace loose, missing, or damaged nuts, bolts, and screws | Tighten fasteners | Semiannually |
3.6 Water & Steam Systems
3.6.1 HVAC Water Distribution Systems
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Controls | Check control valves and balancing valves for proper operation | Clean, lubricate, adjust | Semiannually |
| Fluid System | Perform chemical testing of system water | Treat to ensure proper chemistry, inhibitor levels, and freeze protection | Monthly |
| Fluid System | Check system pressure and expansion tank charge | Adjust pressure; re-charge expansion tank as needed | Quarterly |
| Fluid System | Check automatic air vents and manual bleeds for trapped air | Bleed air from system; verify auto-vents function properly | Quarterly |
| Fluid System | Check strainers for debris accumulation | Clean strainer baskets | Quarterly |
| Fluid System | Check differential pressure across distribution system at primary/secondary interfaces | Adjust variable speed pump or bypass valve to maintain design differential pressure | Quarterly |
| Fluid System | Inspect piping, fittings, and valves for evidence of leaks or corrosion | Record location of identified leaks; repair as required | Annually |
| Fluid System | Verify flow rates at key points in the system match design values | Adjust balancing valves; document deviations from design | Annually |
| Fluid System | Flush low-point drains and check for sediment accumulation | Drain sediment; clean strainers; document sediment color and quantity | Annually |
| Fluid System | Inspect make-up water meter or feed valve for excessive consumption | Investigate cause of high make-up water use; check for leaks or open vents | Annually |
| Safety | Check pressure reducing valves and relief valves for proper operation | Test relief valves; adjust pressure reducing valves as needed | Annually |
| Structural | Check insulation on piping for integrity and vapor barrier continuity | Record damage locations; repair or replace insulation as needed | Annually |
3.6.2 Steam Distribution Systems
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Controls | Check control valves and actuators for proper operation | Clean, lubricate, adjust; repair or replace as needed | Semiannually |
| Fluid System | Perform chemical testing of condensate return and feedwater | Treat to ensure proper chemistry; verify inhibitor and pH levels | Monthly |
| Fluid System | Check strainers at key locations for debris accumulation | Clean strainer baskets | Quarterly |
| Fluid System | Inspect condensate return lines and receivers for leaks | Record location of leaks; repair as required | Quarterly |
| Fluid System | Check pressure reducing valves for proper operation and setpoints | Adjust setpoints; service or replace valves as needed | Semiannually |
| Fluid System | Inspect steam distribution piping and fittings for leaks or corrosion | Record damage locations; repair as required | Annually |
| Mechanical | Check steam traps throughout the distribution system for operation | Test each trap; replace failed-open or failed-closed traps | Quarterly |
| Mechanical | Survey steam distribution piping for unusually hot surfaces indicating failed-open traps | Use infrared thermometer or camera to identify failed traps; replace immediately | Quarterly |
| Mechanical | Check condensate pump operation for vibration, noise, and leaks | Lubricate; repair or replace as needed | Annually |
| Safety | Verify safety relief valves operate correctly | Test relief valves; replace if failed or out of calibration | Annually |
| Structural | Check insulation on steam and condensate piping for integrity | Record damage locations; repair or replace insulation as needed | Annually |
| Structural | Inspect pipe supports, hangers, and expansion loops/joints for movement and wear | Adjust supports; replace worn expansion joints; verify pipe can move freely | Annually |
3.6.3 Coils and Radiators
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Biological | Check drain pan and condensate drain line for biological growth and blockage (cooling coils) | Clean and verify proper drainage | Quarterly |
| Controls | Check control valves and actuators for proper operation | Clean, lubricate, adjust | Semiannually |
| Fluid System | Inspect coil and associated piping for evidence of leaks or corrosion | Record location of identified leaks; repair as required | Annually |
| Fluid System | Check water or steam supply and return connections for proper flow | Verify flow rates; bleed air from coil as needed | Annually |
| Fluid System | Verify coil entering and leaving water temperatures match design values | Investigate low delta-T syndrome; adjust flow or clean coil surfaces | Annually |
| General | Inspect radiator surfaces and enclosures for dirt accumulation | Clean as needed to remove buildup | Annually |
| General | Inspect coil casing and frame for corrosion or structural damage | Treat corrosion; repair or replace damaged casing sections | Annually |
| Heat Exchange | Check for fin damage and fouling on coil surfaces | Clean and restore fins as needed | Annually |
| Structural | Inspect insulation on coil piping for integrity | Record damage locations; repair or replace insulation as needed | Annually |
3.7 Specialized Systems
3.7.1 Economizers – Air-Side
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Airflow | Verify outdoor air intake screens and louvers are clear of debris | Clean screens and louvers; remove obstructions | Annually |
| Airflow | Measure outdoor airflow at 100% economizer position and compare to design | Adjust damper stops or actuator stroke; document airflow deviations | Annually |
| Controls | Verify economizer control sequence activates and deactivates correctly | Adjust control setpoints or sequences as needed | Quarterly |
| Controls | Verify economizer is not locked out (stuck in min position or disabled) | Override and test actuator manually; restore automatic control; document fault codes | Quarterly |
| Controls | Check enthalpy or dry-bulb sensors for calibration and proper operation | Calibrate or replace sensors as needed | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Mechanical | Check outdoor air and return air dampers for proper position and operation | Adjust, lubricate, and repair actuators and linkages as needed | Quarterly |
| Mechanical | Check damper actuators for proper stroke and response to control signal | Lubricate and align; replace actuators if unresponsive | Semiannually |
| Mechanical | Inspect damper blades and seals for damage or air leakage | Replace worn seals; repair or replace damaged blades | Annually |
| Mechanical | Verify relief air or exhaust dampers operate correctly in conjunction with economizer | Adjust and lubricate as necessary | Annually |
3.7.2 Outdoor-Air Heat-Exchanging Systems
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Airflow | Check outdoor air intake screens, louvers, and guards for blockage | Clean screens and louvers; remove debris and obstructions | Quarterly |
| Biological | Check drain pan and condensate drain (if applicable) for biological growth and blockage | Clean and verify proper drainage | Annually |
| Controls | Check control system and devices for improper operation | Clean, lubricate, adjust | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Fluid System | For run-around coil systems, check glycol concentration and inhibitor levels | Adjust glycol mix; replenish inhibitors; verify freeze protection is adequate | Annually |
| General | Inspect for cross-contamination between supply and exhaust airstreams | Verify seals and carry-over prevention; repair as needed | Annually |
| General | Verify heat recovery effectiveness against design values | Document deviations; adjust or clean to restore performance | Annually |
| Heat Exchange | Check frost or ice formation on heat exchange media during cold weather | Verify defrost cycle or bypass sequence operates correctly; adjust setpoints | Quarterly |
| Heat Exchange | Check heat exchange media (plates, rotary wheel, or run-around coils) for fouling | Clean media surfaces per manufacturer recommendations | Semiannually |
| Mechanical | Check bypass dampers and actuators for proper operation | Lubricate and adjust; repair or replace as needed | Semiannually |
| Mechanical | Check rotary heat wheel drive motor and belt (if applicable) | Lubricate bearings; correct belt tension and alignment | Semiannually |
| Mechanical | Check purge sector on rotary wheel for proper adjustment | Adjust purge sector to manufacturer specifications | Annually |
3.7.3 Dehumidification and Humidification Devices
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Biological | Check drain pan and condensate drain on dehumidification equipment for biological growth | Clean and verify proper drainage | Quarterly |
| Biological | Inspect humidifier dispersion area of supply duct for moisture or biological growth | Clean affected duct surfaces; adjust steam dispersion tube absorption distance | Quarterly |
| Controls | Check humidity sensors and controls for calibration and proper operation | Calibrate or replace sensors as needed; adjust setpoints | Quarterly |
| Controls | Check control system and devices for improper operation | Clean, lubricate, adjust | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| General | For evaporative humidifiers, check water supply, distribution pan, and media | Clean media; descale water distribution components | Quarterly |
| General | Inspect humidifier distribution tubes or nozzles for scale or blockage | Clean and verify even distribution | Semiannually |
| General | For electrode/infrared steam humidifiers, inspect cylinder or canister and electrodes for scale | Descale or replace cylinder per manufacturer intervals; verify fill/drain cycles | Annually |
| Mechanical | For steam humidifiers, check steam supply, trap, and strainer | Clean and verify proper operation | Quarterly |
| Refrigerant | Check refrigerant system on dehumidification equipment | When outside recommended levels, find and record cause | Annually |
| Safety | Verify safety devices and controls function per manufacturer specifications | Test, clean, and adjust | Annually |
| Structural | Inspect unit housing, ductwork connections, and insulation for moisture damage | Repair insulation; record and address moisture intrusion | Annually |
3.7.4 Water-Source Heat Pumps
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Biological | Check drain pan and condensate drain for biological growth and blockage | Clean and verify proper drainage | Quarterly |
| Compressor | Check compressor oil level/pressure on systems with measurement means | When outside recommended levels, find and record cause | Annually |
| Controls | Check control system and thermostat for proper operation | Clean, calibrate, adjust | Semiannually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Fluid System | Check entering water temperature and flow rate against design values | Verify loop temperatures are within design range; document anomalies | Quarterly |
| Fluid System | Check water loop pressure differential across the heat pump unit | Verify isolation valves are open; clean in-line strainer; document pressure deviations | Quarterly |
| Fluid System | Check water-side coil and connections for leaks or fouling | Record leak locations; clean coil as needed | Annually |
| General | Check air filter for particulate accumulation | Clean or replace filter as needed | Quarterly |
| Heat Exchange | Inspect refrigerant-to-water heat exchanger for fouling (coaxial or plate-frame) | Flush or chemically clean heat exchanger; restore flow and effectiveness | Annually |
| Mechanical | Check fan motor and blower assembly for noise and vibration | Lubricate bearings; clean fan impeller | Semiannually |
| Refrigerant | Check refrigerant system temperatures and pressures | When outside recommended levels, find and record cause | Annually |
| Refrigerant | Verify reversing valve operation in both heating and cooling modes | Test switchover; clean and adjust as needed | Annually |
| Refrigerant | Perform refrigerant leak detection survey | Repair leaks; document per EPA requirements; recharge as needed | Annually |
| Structural | Inspect unit casing and access panels for integrity | Replace fasteners as needed; seal gaps | Annually |
3.7.5 Control Systems
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Controls | For pneumatic systems, check compressed-air system for proper operation and oil carryover | Clean and lubricate as needed | Monthly |
| Controls | For pneumatic systems, check for proper air pressure | Clean, lubricate, adjust | Monthly |
| Controls | Verify no equipment left in override (hand/OFF instead of auto) locally or through BMS | Make corrections as required | Monthly |
| Controls | Review BMS trend logs for setpoint deviations, short-cycling, or hunting | Adjust PID tuning parameters; repair faulty sensors or actuators | Monthly |
| Controls | For humidity control systems, measure relative humidity | Clean, lubricate, adjust | Quarterly |
| Controls | Check alarms and alarm history | Note and respond as required | Quarterly |
| Controls | Verify CO2 demand-controlled ventilation (DCV) sensors are calibrated and functioning | Calibrate or replace CO2 sensors; verify DCV sequence adjusts outdoor air correctly | Quarterly |
| Controls | Check control system and devices for improper operation | Clean, lubricate, adjust | Semiannually |
| Controls | Check time-of-day schedule for consistency with facility operation | Adjust schedule as needed | Semiannually |
| Controls | Check set points, trended points, time schedules | Note and respond as required | Semiannually |
| Controls | Simulate alarm condition to confirm email/text notification works | Restore as required | Semiannually |
| Controls | For pneumatic systems, check pneumatic lines for blockages | Clean as needed | Annually |
| Controls | Check that backup of digital control program is current | Update when not current | Annually |
| Controls | Verify actuator movement and device response to control output | Lubricate and align as needed | Annually |
| Controls | Change building management system interface user authentication passwords | Make the change | Annually |
| Controls | Perform functional test of all BMS-monitored points — verify values match field measurements | Recalibrate sensors; repair or replace failed points; document discrepancies | Annually |
| Controls | Review cybersecurity posture of BAS network — check patch levels, open ports, and access logs | Apply firmware/software patches; close unnecessary ports; review access control lists | Annually |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Semiannually |
| Electrical | Check motor contactor for pitting or damage | Clean and tighten electrical connections | Annually |
| Electrical | Check battery backup and verify proper operation | Clean and maintain batteries as needed | Annually |
3.7.6 Terminal and Control Boxes (VAV, Fan-Powered, Bypass)
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Airflow | Check VAV box damper operation and verify flow tracking to setpoint | Calibrate flow sensor; adjust actuator and damper | Quarterly |
| Airflow | Verify VAV box is not stuck at minimum or maximum position during normal operation | Test full stroke of damper; repair or replace failed actuator; recalibrate flow sensor | Quarterly |
| Airflow | Verify minimum and maximum airflow setpoints match design intent | Adjust setpoints; document deviations from design | Annually |
| Airflow | Spot-check zone airflow with balometer against design CFM values | Adjust balancing dampers; update setpoints; document deficiencies | Annually |
| Controls | Check room thermostat and zone sensor for proper calibration and operation | Calibrate or replace sensors as needed; adjust setpoints | Quarterly |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Annually |
| Electrical | For electric reheat coils, inspect elements and verify over-temperature limit switch operation | Test limit switch; replace failed elements or safety devices | Annually |
| General | For fan-powered boxes, check filter for particulate accumulation | Clean or replace filter as needed | Quarterly |
| Heat Exchange | Check heating coil (electric or hot water) operation at heating setpoint | Verify coil staging; check valve or contactors; clean and adjust | Semiannually |
| Mechanical | For fan-powered boxes, check fan motor and impeller for noise and vibration | Lubricate bearings; clean fan impeller | Semiannually |
| Mechanical | Check damper actuator for proper stroke and response to control signal | Lubricate and align; replace actuators if unresponsive | Annually |
| Mechanical | For bypass boxes, verify proper operation at both high and low flow conditions | Clean and adjust; verify bypass damper operation | Annually |
| Structural | Inspect flex duct connections to terminal unit for leakage or damage | Re-seal or replace flex duct connections as needed | Annually |
3.8 Power Generation
3.8.1 Engines – Microturbines
| Category | Inspection Task | Maintenance Task | Frequency |
|---|---|---|---|
| Combustion | Check fuel supply pressure, valve operation, and supply line integrity | Clean and verify proper operation; record any leaks | Monthly |
| Controls | Check control system and devices for improper operation; review alarm history | Note and respond to alarms; clean and adjust controls | Monthly |
| Documentation | Record and trend turbine operating data (power output kW, inlet air temp, exhaust temp, fuel flow) | Compare against baseline; flag performance degradation trends | Monthly |
| Electrical | Check control box for dirt, debris, loose terminations | Clean and tighten electrical connections | Semiannually |
| Electrical | Check variable-frequency drive or power electronics | Clean housing, tighten connections, clean/replace air filter | Semiannually |
| Electrical | Check generator output and power quality | Verify output meets specifications; document anomalies | Annually |
| Electrical | Test grid interconnect protection relays (anti-islanding, frequency, voltage) | Verify trip setpoints meet utility requirements; document test results | Annually |
| Fluid System | Check heat recovery system (hot water or steam) for proper temperatures and flow | Verify heat recovery effectiveness; document deviations from design | Quarterly |
| General | Check air intake filter for particulate accumulation | Clean or replace as needed | Quarterly |
| Heat Exchange | Check recuperator and heat recovery components for fouling or damage | Clean and restore as needed | Semiannually |
| Mechanical | Inspect turbine and combustion components per manufacturer schedule | Clean and adjust; replace wear components per manufacturer intervals | Annually |
| Mechanical | Inspect vibration isolation mounts and equipment anchor bolts | Tighten fasteners; replace deteriorated isolation mounts | Annually |
| Safety | Verify proper operation of safety devices and interlocks | Test, clean, lubricate, and adjust | Annually |
| Structural | Check exhaust system and connections for leaks or deterioration | Record leak locations; repair as required | Quarterly |
4. Inspection & Maintenance Frequencies
4.1 Baseline Frequencies
The frequencies listed in the equipment tables represent the minimum required for compliance.
Monthly
12 times per year — typically for water treatment, fuel system checks, and critical control systems
Quarterly
4 times per year — common for filters, drain systems, and seasonal equipment
Semiannually
2 times per year — typical for mechanical components, belts, and control systems
Annually
Once per year — common for comprehensive inspections, bearings, and heat exchangers
4.2 Adjusting Frequencies
Increase Frequency When:
- Unacceptable conditions found during two successive inspections
- Equipment operates in harsh environments
- Critical equipment supporting critical operations
- High utilization — equipment running extended hours
- Warranty requirements mandate more frequent tasks
Decrease Frequency When:
- Acceptable conditions observed during three successive inspections
- Seasonal shutdown — equipment not in use
- Backup equipment not in primary service
⚠️ Important: Document All Frequency Changes
- Documented with the reason for the change
- Based on actual equipment condition data
- Approved by the responsible party
- Reviewed periodically to ensure effectiveness
4.3 Climate and Operational Considerations
| Situation | Impact on Frequency | Example Adjustment |
|---|---|---|
| Cooling tower/chiller shutdown during winter | Suspend during shutdown, increase before/after | No monthly inspections during shutdown months |
| Heating system shutdown during summer | Suspend during shutdown, increase before/after | Perform pre-season checkout in fall |
| New equipment with old as backup | Reduce frequency on backup unit | Backup chiller inspected annually vs. quarterly |
| Construction/renovation activity | Increase filter changes | Monthly filter checks vs. quarterly |
| High pollen season | Increase filter and coil inspections | Monthly checks during spring months |
| Extreme weather periods | Increase system monitoring | Weekly checks during heat waves |
5. Condition Indicators & Performance Metrics
5.1 Physical Condition Indicators
Visual/Structural Issues:
- Deformation, perforation, discoloration, or contamination of component surfaces
- Fluid or vapor leakage evidence
- Excessive or abnormal noise or vibration
- Loose or missing fasteners
- Unusual ice, frost, or condensate formation
- Worn or damaged electrical insulating materials
- High levels (>20% area) of surface corrosion or scale accumulation
Contamination Issues:
- High levels of accumulated dirt or sludge
- Visible biological growth (fungi, algae, or bacteria)
- Biological growth determined by test results
⚠️ Safety First
When toxic fumes or smoke are detected, test before entering area or confined space. Follow all OSHA safety requirements.
5.2 Performance Indicators
| Performance Metric | Unacceptable Condition | Typical Causes |
|---|---|---|
| Filter pressure drop | Exceeds manufacturer specification | Clogged filters, improper filter installation |
| Chiller leaving water temperature | Cannot produce design temperature | Low refrigerant charge, fouled heat exchangers, mechanical issues |
| Air handler airflow | Not within design requirements | Dirty coils/filters, belt slippage, fan issues, duct restrictions |
| Space temperature | Exceeds setpoint requirements | Insufficient capacity, control issues, distribution problems |
| Condensing water temperature | Rises beyond design | Cooling tower issues, scaling, low water flow |
| Energy consumption | Exceeds design-basis without operating hours or function change | Degraded efficiency, simultaneous heating/cooling, control issues |
| System delivery | Incorrect air/water flow, current draw, pressure drop | Component wear, fouling, mechanical issues, control problems |
5.3 Measuring and Trending
Key Performance Indicators (KPIs) to Track:
- Energy Use Intensity (EUI) — kBtu/sq ft/year
- Thermal comfort complaints — Number per month
- IAQ complaints — Number per month
- Unplanned maintenance events — Number per quarter
- Equipment runtime hours — Hours per month
- Filter life — Days between changes
- Refrigerant added — Pounds per year (indicates leaks)
- Water treatment chemical usage — Gallons per month
- Maintenance cost per square foot — $/sq ft/year
6. Industry Best Practices
6.1 Cost-Benefit Analysis
For a 100,000 sq ft commercial building:
- Reactive approach: $250,000 – $350,000/year maintenance + 15–30% higher energy costs
- Preventive approach: $175,000 – $225,000/year maintenance + 5–10% higher energy costs
- Net annual savings: $75,000 – $125,000 from preventive maintenance
6.2 Building Commissioning Integration
Maintenance programs are most effective when integrated with building commissioning activities, which provide baseline performance data, document design intent, and establish proper control sequences.
6.3 Technology Integration
Modern maintenance programs leverage Building Automation Systems (BAS), Computerized Maintenance Management Systems (CMMS), and mobile technology to improve scheduling, documentation, and trending.
6.4 Safety Considerations
All maintenance activities must prioritize Lockout/Tagout (LOTO) procedures, appropriate Personal Protective Equipment (PPE), and confined space entry protocols per OSHA requirements.
6.5 Documentation Best Practices
Comprehensive documentation including equipment inventory, task completion records, condition data, work orders, and cost tracking is essential for program success and continuous improvement.
7. Maintenance Program Elements
7.1 Equipment Inventory
Create a comprehensive inventory of all HVAC systems and equipment that impact thermal comfort, energy efficiency, and indoor air quality. The inventory must include:
- Manufacturer information
- Equipment location
- Capacity specifications
- Maintenance program identifier (tag number)
- Installation date and warranty information
- Design parameters and operating conditions
7.2 Maintenance Plan Development
A maintenance plan must be developed specifically for the size, design, scope, criticality, and complexity of the systems serving the facility. The plan must include:
Required Elements:
- Task Description: Detailed description of each inspection and maintenance task
- Task Frequency: How often each task must be performed
- Task Schedule: Specific timing for when tasks will be executed
- Responsible Parties: Who will perform each task
- Authorization Process: Who approves the work
- Documentation Procedures: How task completion will be recorded
- Monitoring Procedures: How plan effectiveness will be measured
- Evaluation & Feedback: Process for continuous improvement
7.3 Condition Indicators
Develop specific, measurable indicators for systems and equipment.
Physical Condition Indicators:
- Visual appearance (corrosion, damage, wear)
- Working order (noise, odor, vibration, leaks)
- Cleanliness (dirt accumulation, biological growth)
- Structural integrity (proper mounting, secure fasteners)
Performance Indicators:
- Air volume flow rates vs. design
- Water flow rates vs. design
- Temperature delivery vs. setpoints
- Pressure drops across filters and coils
- Energy consumption vs. baseline
- Refrigerant pressures and temperatures
7.4 Maintenance Program Objectives
Establish measurable objectives that define desired outcomes based on design documents, manufacturer materials, industry standards, and owner requirements.
7.5 Program Review & Adjustment
The maintenance program must be reviewed periodically — at minimum at the beginning and end of each performance period.
Critical Review Triggers
Review and adjust the maintenance plan when:
- Unacceptable conditions are found during two successive inspections
- Acceptable conditions are observed during three successive inspections (consider reducing frequency)
- Climate or operational requirements change significantly
- Equipment is modified, replaced, or added
- Building use or occupancy changes
Summary and Key Takeaways
1. Establish a Comprehensive Program
Create an inventory, develop a maintenance plan, set objectives, and define condition indicators before beginning work.
2. Follow Minimum Requirements
Include all applicable tasks from the equipment tables at minimum specified frequencies.
3. Document Everything
Record all task completions, findings, conditions, and corrective actions for trending and analysis.
4. Monitor and Adjust
Review program effectiveness regularly and adjust task frequencies based on actual conditions.
5. Continuous Improvement
Use condition data and performance metrics to continuously improve the maintenance program.
6. Prioritize Safety
Ensure all maintenance activities follow proper safety procedures and personnel are properly trained.
Benefits of Following This Guide
- Energy Savings: Well-maintained systems operate 10–30% more efficiently
- Extended Equipment Life: Proper maintenance can double equipment service life
- Reduced Operating Costs: Preventive maintenance costs 30–50% less than reactive approaches
- Improved Comfort: Maintained systems consistently deliver design thermal conditions
- Better Indoor Air Quality: Regular maintenance prevents biological growth and ensures proper ventilation
- Compliance: Documented maintenance program demonstrates due diligence
- Fewer Emergencies: Preventive approach reduces unexpected failures and downtime
Disclaimer: This guide represents industry best practices compiled from multiple sources. It is provided for informational purposes only and does not constitute professional advice. Consult with qualified HVAC professionals, engineers, and local authorities for specific requirements applicable to your facility. Always follow manufacturer recommendations and local codes.