HVAC Seasonal Maintenance Checklist

Regular HVAC maintenance prevents breakdowns, extends equipment life, and keeps energy bills low. Use this checklist for your seasonal tune-ups — both as a technician guide and as a customer-facing document that shows the thoroughness of your service.

Spring/Summer — Cooling System Tune-Up

Outdoor Unit (Condenser)

• Clear debris — Remove leaves, grass clippings, and dirt from around the unit. Maintain 2 feet of clearance on all sides.
• Clean condenser coils — Use a coil cleaner and garden hose (not pressure washer). Dirty coils reduce efficiency by up to 30%.
• Inspect fan blades — Check for cracks, damage, or wobble. Replace if needed.
• Check condenser fan motor — Verify smooth operation and proper amp draw.
• Inspect electrical connections — Tighten all connections. Loose connections cause overheating.
• Check contactor — Look for pitting or burn marks. Replace if worn.
• Verify proper refrigerant charge — Measure superheat and subcooling. Add or recover refrigerant as needed.
• Inspect refrigerant lines — Check for leaks, damage, and proper insulation on the suction line.

Indoor Unit (Evaporator/Air Handler)

• Replace or clean air filter — Dirty filters restrict airflow and strain the system.
• Clean evaporator coil — Use a no-rinse coil cleaner. Frozen or dirty coils indicate problems.
• Check condensate drain — Clear the drain line with a wet/dry vacuum or compressed air. Pour a cup of bleach to prevent algae growth.
• Inspect blower wheel and motor — Clean the blower wheel. Check motor amps and bearings.
• Check electrical connections — Tighten and inspect all wiring.
• Test capacitors — Measure microfarad rating. Replace if out of spec.

Thermostat and Controls

• Test thermostat operation — Verify heating and cooling modes switch correctly.
• Check temperature accuracy — Compare thermostat reading to an independent thermometer.
• Verify programming — Help the customer set an efficient schedule.
• Check batteries — Replace if applicable.

System Performance

• Measure supply and return temperatures — Typical split is 15-20°F across the evaporator.
• Check airflow at registers — All vents should be open and unobstructed.
• Measure static pressure — High static pressure indicates ductwork issues.
• Cycle the system — Verify proper startup, operation, and shutdown.

Fall/Winter — Heating System Tune-Up

Gas Furnace

• Inspect heat exchanger — Look for cracks or corrosion. A cracked heat exchanger is a carbon monoxide hazard.
• Clean and inspect burners — Remove and clean. Check for proper flame pattern (blue, steady).
• Check ignition system — Clean flame sensor or replace igniter as needed.
• Inspect flue/vent — Check for obstructions, proper slope, and secure connections.
• Test gas pressure — Verify manifold pressure matches manufacturer specifications.
• Check CO levels — Measure carbon monoxide in the flue and living space.
• Replace air filter — Clean filter ensures proper airflow and efficiency.
• Inspect and clean blower — Remove and clean the blower wheel. Check motor amps.
• Test safety controls — Verify high-limit switch, pressure switches, and rollout switches operate correctly.

Heat Pump (Heating Mode)

• All cooling season checks above — Heat pumps use the same components year-round.
• Test defrost cycle — Verify the defrost board initiates and completes defrost properly.
• Check reversing valve — Verify it switches between heating and cooling modes.
• Test auxiliary/emergency heat — Verify backup heat strips or furnace activates correctly.
• Inspect outdoor unit for ice buildup — Some frost is normal, but heavy ice indicates problems.

Customer Communication Template

After completing the tune-up, provide the customer with a summary: