HVAC maintenance checklist: a residential spring cooling and fall heating tune-up your techs can follow

Two customers can pay for the same "tune-up" and get very different visits. One gets a filter change and a sticker. The other gets readings recorded, a cleaned condensate line, a checked heat exchanger and a written note about a weak capacitor. Only the second one prevents a July no-cool call.

This checklist is the second kind. It is written for residential split systems, furnaces and heat pumps. Hand it to techs as the standard, then adjust for the equipment you see most. For how to fit these visits into a busy season, see the preventive maintenance scheduling guide.

Before you start (every visit)

1. Confirm the customer, the equipment on file and any notes from the last visit.
2. Ask the customer: any noises, smells, uneven rooms, short cycling, high bills or water around the unit since the last visit?
3. Record the nameplate data (model, serial, age) for the indoor and outdoor units if it is not on file.
4. Photograph the equipment as found.
5. Kill power at the disconnect and the service switch before opening panels, and verify with a meter.

Spring cooling tune-up

Indoor unit

1. Filter: check, replace or clean. Record the size. The DOE's Energy Saver guide advises homeowners to clean or replace air conditioner filters once a month or as recommended, so tell the customer how often their filter type needs it.
2. Evaporator coil: inspect for dirt and clean as needed.
3. Condensate drain: flush the line, check the trap, confirm the pan drains and is not rusted through.
4. Condensate safety switch or float: test that it shuts the system off.
5. Blower: inspect the wheel for dirt, check the motor, record amp draw against nameplate.
6. Electrical connections: tighten and inspect for heat damage.
7. Ductwork at the unit: look for disconnected or leaking joints.

Outdoor unit

8. Clear debris, vegetation and anything stored against the unit.
9. Condenser coil: inspect and rinse or clean per the manufacturer.
10. Fins: straighten bent fins with a fin comb.
11. Capacitor: test and record the reading against its rating.
12. Contactor: inspect for pitting and burning.
13. Fan motor and blade: check for wobble, noise and amp draw.
14. Electrical: disconnect, whip and connections in good condition.
15. Refrigerant lines: insulation intact, no oil stains suggesting a leak.
16. Unit level on its pad.

System running

17. Thermostat: calls for cooling correctly, setpoint and schedule match the customer's wishes.
18. Record outdoor temperature, indoor temperature and humidity.
19. Record supply and return air temperatures and compare the temperature split to the manufacturer's guidance.
20. Record refrigerant pressures and superheat or subcooling as the manufacturer specifies for the metering device. Leak search if readings suggest a low charge. Do not top off without finding the leak.
21. Record compressor amp draw against nameplate.
22. Listen for abnormal noise and check for vibration.

Fall heating tune-up

Gas furnace

1. Filter: check, replace or clean. The same DOE guide advises cleaning or replacing furnace filters once a month or as recommended.
2. Venting: inspect the flue from the furnace to the termination for disconnections, corrosion, blockage and proper slope. The CPSC recommends having heating systems professionally inspected and serviced every year, including chimneys and flues for blockages, corrosion, and loose or disconnected connections.
3. Heat exchanger: inspect for cracks, rust and signs of flame rollout, per the manufacturer's procedure.
4. Burners: clean, check flame pattern.
5. Igniter and flame sensor: inspect, clean the flame sensor, record microamps if the manufacturer gives a range.
6. Gas pressure: measure and set per the nameplate and manufacturer.
7. Gas leak check on the appliance connections.
8. Combustion analysis where your company requires it and the manufacturer provides a procedure.
9. Safeties: high limit, rollout switches and pressure switch operate.
10. Inducer motor and blower: inspect, record amp draw.
11. Condensate (high-efficiency furnaces): flush the trap and drain.
12. Temperature rise: measure and compare to the range on the nameplate.

Heat pump (heating mode)

13. Outdoor coil clear and clean.
14. Defrost cycle: verify it initiates and terminates.
15. Reversing valve: switches correctly.
16. Auxiliary or emergency heat strips: operate and draw the right current.
17. Record pressures, amp draw and supply and return temperatures.

Every heating visit

18. CO alarms: ask whether the home has working CO alarms. The CPSC says they should be installed on each level of the home and outside sleeping areas.
19. Thermostat: calls for heat correctly, schedule set.
20. Humidifier, if present: pad or panel, water supply, drain.

Close-out (every visit)

1. Restore power, run a full cycle and confirm normal operation.
2. Photograph the equipment as left.
3. Record every reading on the work order, not just "OK".
4. Write recommendations in plain language with a priority: safety, soon, monitor.
5. Show the customer the filter and anything you found. Tell them when their next visit is due.

Why record readings instead of ticking boxes

A tick says the tech looked. A reading says what they saw, and it is the only way to spot a trend. A capacitor at the low edge of its rating this spring and below it next spring is a planned replacement instead of a July no-cool call. A furnace temperature rise drifting toward the edge of its nameplate range over two visits points at airflow before the customer feels it.

There is also a scheduling reason. Tune-ups pile up in spring and fall, and a visit that takes 45 minutes on one system takes 90 on another. Recording what was done, and how long it took, gives you real durations for next season's booking (more on that in how to schedule HVAC technicians). If you plan these visits by zone, the maintenance agreement scheduling entry covers the routing side. In CrewLink, time on site is recorded when the tech marks the job done, and future bookings use it.

How to adapt it

• Split it by equipment type. A boiler, a ductless mini-split or a packaged rooftop unit each needs its own short list.
• Set a time standard. Decide how long a cooling visit and a heating visit should take for each equipment type, and plan the day around it. The HVAC scheduling page covers why tune-up season is hard on the schedule.
• Make some items mandatory. Venting, heat exchanger and CO alarm questions on every heating visit, no exceptions.
• Give the customer a copy. A one-page summary with readings and recommendations is what makes a maintenance plan feel worth renewing. The maintenance agreement checklist covers what the plan itself should promise.

Common questions

What is included in an HVAC tune-up?

A cooling tune-up typically covers the filter, evaporator and condenser coils, condensate drain, electrical parts like capacitors and contactors, refrigerant readings, airflow and thermostat. A heating tune-up covers the filter, venting, heat exchanger, burners, ignition, gas pressure, safeties, temperature rise and thermostat. The checklist above gives the full order.

How often should residential HVAC be serviced?

A common plan structure is one cooling visit in spring and one heating visit in fall. The CPSC recommends having the heating system professionally inspected and serviced every year. Filters need attention far more often: the DOE suggests monthly or as the filter maker recommends.

How long does an HVAC maintenance visit take?

It depends on the equipment and how dirty it is. Measure your own: record time on site for each tune-up by equipment type for one season and use the average for next season's booking, rather than a single guess for every system.

Can a tech add refrigerant during a tune-up?

Only a technician with the right EPA Section 608 certification should handle refrigerant. If readings suggest the system is low, the better practice is to find and repair the leak before adding refrigerant, and to document the readings.