A well-maintained heat pump lasts 15–20 years. A neglected one fails in 8–10. The difference is a few hours of maintenance per year. Here is exactly what to do, season by season, plus what a professional tune-up should include and what it should cost.
Monthly: Tasks That Take 5 Minutes
- Check and replace the air filter — Every 1–3 months. A dirty filter reduces airflow, forcing the system to work 15% harder. Pleated MERV 8 filters are the sweet spot for most homes — they trap dust and pollen without restricting airflow. MERV 13+ filters protect better but may require more frequent changes.
- Inspect the outdoor unit — Clear leaves, grass clippings, snow, or debris from within 2 feet of the unit. Restricted airflow is the #1 cause of heat pump failure.
- Listen — Unusual sounds (grinding, squealing, rattling) mean something is wrong. A healthy heat pump produces a steady hum from the compressor and airflow noise from the fan.
Spring: Cooling Season Preparation (April–May)
- Deep-clean the outdoor coil — Turn off power at the breaker. Remove the outer casing. Gently spray the coil fins with a garden hose (NOT a pressure washer — it bends the delicate aluminum fins). Use a fin comb ($12 at any hardware store) to straighten bent fins.
- Clean the condensate drain line — Pour 1 cup of white vinegar into the drain line to kill algae and prevent clogs. A clogged drain line triggers a safety float switch that shuts down your system on the hottest day of the year.
- Check refrigerant lines — The insulated line (the larger of the two copper pipes) should feel cold to the touch when the system is running in cooling mode. If it is warm or room temperature, you may have a refrigerant leak — call a pro.
Fall: Heating Season Preparation (October–November)
- Test the defrost cycle — On a cold morning (below 40°F), observe the outdoor unit. It should periodically enter defrost mode (steam rising from the unit, temporary shift in sound). If ice builds up and does not melt within 30 minutes, the defrost control board or sensor may need replacement.
- Inspect ductwork — Walk your basement or attic with a flashlight. Look for disconnected joints, crushed sections, or visible gaps. Use foil tape (not duct tape — it dries out) to seal minor leaks. Duct sealing can reduce energy loss by 20%.
- Switch thermostat to heating mode — Set to 68°F for optimal balance of comfort and efficiency. Each degree above 68 adds approximately 3% to your heating bill.
Professional Tune-Up: What It Should Include
Schedule professional maintenance once per year — ideally in spring before cooling season. Expect to pay $100–$200 for a comprehensive tune-up. The technician should:
- Measure refrigerant charge (subcooling and superheat)
- Inspect electrical connections and tighten if needed
- Test capacitors (weak capacitors cause compressor failure)
- Check contactors for pitting or burning
- Measure temperature drop across the indoor coil (should be 15–20°F in cooling mode)
- Inspect and clean the blower wheel
- Test the thermostat calibration
- Check the condensate pump operation
Signs Your Heat Pump Needs Immediate Attention
- Ice on the outdoor unit in summer — Low refrigerant or restricted airflow
- Short cycling (turns on and off every 2–5 minutes) — Oversized system or thermostat issue
- No air from vents — Blower motor failure or frozen indoor coil
- Burning smell when first turned on for the season — Dust burning off the heat strips is normal for 15–20 minutes. Persistent burning smell = electrical problem
- Electricity bill spikes 40%+ — Refrigerant leak, stuck reversing valve, or failing compressor