A commercial HVAC preventative maintenance checklist is the list of tasks a technician completes on each piece of equipment at each visit, with the readings recorded so the next visit can be compared against it. The checklist below is the one SBS-NC's own technicians work from, organized two ways: by season, because most of it is driven by the cooling and heating cutovers, and by equipment type, because a chiller plant and a rooftop fleet need different lists. Print it, hand it to whoever maintains your buildings, and ask for the readings, not just the check marks.
How to use this checklist
- One list per unit, per visit. A report that says “PM completed” for a building is not a maintenance record. Each rooftop unit, split system, chiller, boiler, and tower gets its own line items and its own readings.
- Record numbers, not just checks. Refrigerant pressures and superheat or subcooling, amp draws against nameplate, static pressure, approach temperature on a chiller, combustion readings on a boiler. Trends catch failures that a single visit cannot.
- The manufacturer's schedule wins. This checklist is general industry guidance built on ASHRAE/ACCA Standard 180; if the equipment manual calls for something more often, follow the manual.
- Repairs found on a visit are quoted, not assumed. A checklist finds problems; it does not authorize fixing them. The unit report should list what was found, what it will cost, and what happens if it waits.
Commercial HVAC maintenance checklist by season
Semi-annual programs do the spring and fall visits. Quarterly programs add the summer and winter checks, which is what keeps restaurants, high-dust sites, and 24/7 buildings out of trouble between cutovers.
| Season | Timing | Checklist |
|---|---|---|
| Spring (cooling start-up) | March to May, before the first sustained cooling load | Replace filters; clean condenser and evaporator coils; check refrigerant charge by superheat or subcooling and look for oil at joints; test capacitors, contactors, and motor amps against nameplate; inspect belts, pulleys, and bearings; clear condensate drains and pans and treat for growth; verify economizer dampers and sensors; test thermostats, setpoints, and schedules; confirm safeties; start chillers and towers per the plant list below. |
| Summer (mid-season check) | July or August | Filters again on high-runtime and kitchen sites; condensate drains and pans; condenser coil condition on units near cottonwood, grass clippings, or dust; amp draws and head pressure under full load; check for short-cycling and alarm history; cooling tower chemistry and fill condition. |
| Fall (heating start-up) | September to November, before the first heating call | Replace filters; inspect heat exchangers for cracks and corrosion; clean burners and check ignition, flame sensor, and gas pressure; combustion analysis on boilers and larger furnaces; test limits, rollout switches, and pressure switches; inspect flues and draft; check heat pump reversing valves and defrost; verify freeze protection on coils and towers; winterize or lay up towers. |
| Winter (mid-season check) | January or February | Filters on high-runtime sites; burner and flame readings on boilers carrying the building; condensate traps on condensing boilers and furnaces; economizer minimum position; humidity control in lab and healthcare space; review alarm logs and plan the spring repair list. |
Checklist by equipment type
Rooftop units (RTUs) and split systems
The bulk of most commercial programs. The visit list below is what SBS-NC includes at the per-unit rate ($200 for the first rooftop or split unit at a site, $149 for each additional, $149 for every unit once a site has four or more). More on what rooftop units and commercial split systems need is in those guides.
| Task | Frequency | What gets recorded |
|---|---|---|
| Filters replaced (correct size and MERV) | Every visit; monthly on kitchens and high-dust sites | Filter sizes and quantities per unit |
| Condenser coil cleaned, evaporator coil inspected and cleaned as needed | Spring, plus summer where the roof environment is dirty | Coil condition before and after; fin damage |
| Refrigerant circuit checked (superheat/subcooling, sight glass, leak indicators) | Spring and summer | Pressures, superheat, subcooling, ambient; any oil traces |
| Electrical: capacitors, contactors, wiring, disconnects, motor amps | Every visit | Capacitor readings, amps vs nameplate, burnt or pitted contacts |
| Belts, pulleys, bearings, blower wheel | Every visit | Belt condition and tension, bearing noise or heat, wheel cleanliness |
| Condensate drains, pans, traps, float switches | Every visit | Drain cleared, pan treated, float switch tested |
| Economizer dampers, actuators, sensors, minimum position | Spring and fall | Damper travel, sensor readings, minimum OA position |
| Heat exchanger, burners, ignition, flame sensor, gas pressure, limits | Fall, plus winter on high-runtime sites | Combustion readings where applicable, limit tests, heat exchanger condition |
| Thermostat or controller, schedules, setpoints, alarms | Every visit | Setpoints, schedule verified, alarm history cleared and noted |
| Cabinet, panels, curb, roof penetrations, unit tag | Every visit | Rust, missing screws or panels, water intrusion, tag legible |
VRF systems
VRF needs the same filter and coil work on every indoor unit plus platform-specific diagnostics; see the VRF guide.
| Task | Frequency | What gets recorded |
|---|---|---|
| Indoor unit filters and coils, condensate pumps and drains | Every visit; quarterly in kitchens and dusty spaces | Units serviced, pump tests |
| Outdoor unit coils, fan motors, compressor amps | Spring and fall | Amps vs nameplate, coil condition |
| Refrigerant charge and leak check at branch boxes and joints | Annually and whenever error codes point to charge | Charge status, any leak locations |
| Error-code history and controller settings | Every visit | Codes cleared and listed, settings verified |
Chillers (air-cooled and water-cooled)
Chillers are quoted per machine after a walk-through rather than at the per-unit rate, and the list is longer. The full task table by frequency, with the air-cooled and water-cooled differences, is on the commercial chiller service page; the chiller troubleshooting guide covers what the readings mean when they go wrong.
| Task | Frequency | What gets recorded |
|---|---|---|
| Operating log review: chilled and condenser water temperatures, pressures, approach, amps, run hours | Every visit; daily by building staff on critical plants | Approach temperature trend on evaporator and condenser |
| Condenser cleaning: air-cooled coils washed; water-cooled tubes brushed | Annually at minimum; coils more often in dirty environments | Before and after approach, tube condition |
| Refrigerant leak check and charge verification; purge unit run time on low-pressure machines | Every visit | Leak points, charge status, purge hours |
| Oil analysis and oil filter or drier change on machines with oil | Annually | Lab results: moisture, acid, metals |
| Eddy-current (tube) testing on water-cooled condensers and evaporators | Every 3 to 5 years, or sooner where water treatment has slipped | Tube wall loss map; tubes plugged or replaced |
| Safeties and controls: high and low pressure cutouts, flow switches, freeze protection, setpoints, alarms | Every visit | Test results, alarm history |
| Compressor and motor: vibration, amps, starter or VFD condition, bearings or magnetic-bearing diagnostics | Spring, plus mid-season on 24/7 loads | Vibration readings, amps vs nameplate |
| Water treatment coordination on the condenser water side (with the tower program) | Monthly in season | Chemistry results and cycles of concentration |
Boilers
Boilers carry the whole building in January, so fall is the visit that matters. Boiler types and what each needs are in the commercial boiler guide; service is described on the boiler and cooling tower service page.
| Task | Frequency | What gets recorded |
|---|---|---|
| Combustion analysis and burner tuning | Annually at fall start-up; mid-season on boilers carrying the full building | O2, CO, stack temperature, efficiency |
| Low-water cutoff test, relief valve test, pressure and temperature controls | Annually, with cutoffs tested per the manufacturer's interval | Test results and dates |
| Heat exchanger, refractory, and tube inspection; flue and draft check | Annually | Condition notes, draft readings |
| Water-side condition: chemistry, scale, condensate trap and neutralizer on condensing boilers | Annually, chemistry per the treatment program | Chemistry results, trap and neutralizer serviced |
| Pumps, expansion tank, air separator, zone valves, controls and reset schedule | Fall and winter | Pump amps, tank charge, control settings |
Cooling towers
The water side of a chiller plant and the one piece of equipment with a public-health standard attached to it. The full seasonal list and the terms are in what a cooling tower is and how it works.
| Task | Frequency | What gets recorded |
|---|---|---|
| Clean and disinfect basin, fill, and distribution system | At least twice a year (start-up and shutdown) | Dates, chemicals used, condition found |
| Inspect fill, drift eliminators, louvers, nozzles, and basin | Monthly in season | Scale, slime, damage, plugged nozzles |
| Fan, drive, belts, gearbox, bearings, motor amps, vibration switch | Monthly in season | Amps, vibration, belt condition |
| Makeup float, blowdown valve, overflow, level control | Monthly in season | Operation verified, settings |
| Water chemistry: conductivity, pH, inhibitor, biocide; cycles of concentration | Weekly (treatment program); reviewed monthly | Logged readings |
| Winter prep: drain and dry, or verify basin heaters and heat trace | Fall | Layup condition, heater tests |
| Written water management plan (ASHRAE Standard 188) reviewed | Annually | Plan date and responsible person |
Exhaust fans and make-up air units
| Task | Frequency | What gets recorded |
|---|---|---|
| Belts, pulleys, bearings, motor amps on roof exhaust fans | Spring and fall; quarterly on kitchen exhaust | Belt condition, amps |
| Make-up air filters, burners or coils, dampers, interlocks with exhaust | Spring and fall | Filters changed, damper travel, interlock tested |
| Grease accumulation at kitchen hood exhaust fans and curbs | Quarterly | Condition; hood cleaning vendor flagged if needed |
What this checklist does not replace
- The manufacturer's maintenance schedule for your specific model, which may call for tasks at shorter intervals than the general guidance here.
- ASHRAE/ACCA Standard 180, the industry baseline for inspection and maintenance of commercial building HVAC systems, which this checklist follows but does not reproduce.
- A written water management plan under ASHRAE Standard 188 for any building with a cooling tower, evaporative condenser, or similar water system.
- A repair quote. Anything the checklist finds is written up on the unit report and priced before work starts; see how commercial HVAC repair and diagnostics work.
Turning the checklist into a maintenance contract
A maintenance contract is this checklist with a calendar and a price attached: which units, how many visits a year, what happens on each, and what it costs per visit. SBS-NC's commercial HVAC preventative maintenance page explains the semi-annual, quarterly, and monthly programs and what a contract includes and excludes; the Quick Quote tool turns an equipment list into a budgetary annual range in your browser; and the multi-site PM cost guide covers portfolios. All of it is self-performed by SBS-NC's own technicians across North Carolina, South Carolina, Georgia, Florida, Alabama, and Tennessee.
Preventative maintenance checklist questions
Sources & further reading
- ANSI/ASHRAE/ACCA Standard 180 — Standard Practice for Inspection and Maintenance of Commercial Building HVAC Systems (via DOE Better Buildings)
- U.S. DOE Federal Energy Management Program — Operations and Maintenance Best Practices Guide
- ANSI/ASHRAE Standard 188-2018 — Legionellosis: Risk Management for Building Water Systems
- ENERGY STAR — Building Upgrade Manual, Chapter 5: Retrocommissioning and O&M