Heat Pump Maintenance: What Matters and What Doesn't

Heat pumps run year-round, so they accumulate roughly double the operating hours of a cooling-only air conditioner. Maintenance matters more, and most of what actually matters is free.

What heat pump maintenance actually matters?

1. Change the filter

The single highest-impact maintenance task, and it costs a few dollars.

A restricted filter reduces airflow, which cuts heating and cooling capacity, forces backup heat to run, raises energy use, and in bad cases trips a safety limit and shuts the system down. Prolonged restriction can freeze the indoor coil in cooling mode or overheat components in heating.

How often: every 1–3 months for standard 1-inch filters. Pets, allergies, and construction dust shorten that. Thicker media filters (4–5 inch) may run 6–12 months.

How to tell: hold it up to a light. If light doesn't pass through, replace it.

Higher MERV isn't automatically better — a filter too restrictive for the system reduces airflow and does its own damage. See HVAC air filters and MERV explained.

2. Keep the outdoor unit clear

The outdoor coil has to move air. Anything blocking it reduces capacity in both seasons.

• Clear 18–24 inches around the unit, and check manufacturer clearances
• Trim vegetation — hedges grown in around the unit are extremely common
• Clear snow from sides and top in winter, gently
• Remove leaves and debris from the coil fins and the base
• Ensure drainage — meltwater from defrost cycles must drain away, not pool and refreeze

Never chip ice off the coil. The fins and refrigerant tubing puncture easily. See heat pump defrost cycle.

Other homeowner tasks

Rinse the outdoor coil, gently, once or twice a year. A garden hose from the inside out where accessible, with the power off at the disconnect. Not a pressure washer — it bends fins and drives debris deeper.

Check the condensate drain. The indoor coil produces condensate in cooling mode. A clogged drain causes water damage and, on systems with a float switch, a shutdown. Look for standing water in or below the air handler.

Keep supply and return vents unobstructed. Furniture and rugs over returns starve the system. Closing vents in unused rooms doesn't save money on most systems — it raises static pressure and reduces overall airflow.

Listen. Grinding, screeching, or repeated hard clicking are worth reporting early. A "whoosh" during defrost is normal.

Watch the AUX indicator. If auxiliary heat is on more than expected, something is wrong — see heat pump backup heat explained.

What should a heat pump service include?

A real maintenance visit, not a filter change with an invoice:

• Refrigerant charge verification — measured against manufacturer specs, not guessed
• Airflow and static pressure measurement — this is how duct problems get found
• Electrical checks — capacitor condition, contactor wear, connection tightness, amp draw
• Coil cleaning, indoor and outdoor, as needed
• Condensate drain clearing
• Defrost cycle verification
• Reversing valve operation
• Temperature split across the coil, compared against expected values
• Thermostat calibration and settings review

Ask for the measured numbers, not just "everything looks good". Refrigerant pressures, temperature split, and static pressure are the readings that indicate whether the system is actually performing.

How often does a heat pump need servicing?

Manufacturers typically recommend annual professional service. For a heat pump specifically, twice yearly — before heating and before cooling season — is common, because it runs in both.

Check your warranty terms. Many require documented professional maintenance, and claims have been denied for missing records. If yours does, keep the invoices.

What heat pump services can you decline?

Refrigerant "top-ups" as routine maintenance. Refrigerant isn't consumed. If the charge is low, there's a leak, and adding more without finding it is a recurring bill. See refrigerant leak signs.

Chemical coil cleanings on a coil that isn't dirty. Ask to see it.

UV lights and air purifiers, unless you have a specific reason to want one. They're high-margin add-ons frequently sold as maintenance.

Duct cleaning as a routine item. There's limited evidence it improves performance or air quality in a typical home absent visible contamination, mold, or a rodent problem. Duct sealing is a different thing and often genuinely worthwhile — see ductwork problems and cost.

"Your system is old, you should replace it" delivered during a maintenance visit. Sometimes true — see how long does a heat pump last — but get a second opinion before acting on it.

A simple schedule

Where to go next

• How long does a heat pump last
• Heat pump not heating: troubleshooting
• HVAC air filters and MERV explained
• Run the numbers: electricity cost calculator

More in our heating and cooling guides.