Heat Pump Parts

Heat Pump Parts & Replacement Parts

Heat pumps are built to last, but when they stop heating or cooling, the culprit is usually one of a handful of high-failure parts. The run capacitor is the #1 repair — a $15 to $40 part that fixes most "outdoor unit won't run" complaints. If the compressor clicks on and off or the fan won't spin, the capacitor is your first stop.

Beyond the capacitor, contactors, fan motors, control boards, and reversing valves are the next most common failures. A heat pump losing heat in winter or struggling to cool in summer often points back to one of these parts. OEM parts ensure your system maintains proper refrigerant pressure and electrical safety — critical for sealed-system efficiency.

• Run capacitors: outdoor unit won't run, compressor clicks, fan motor stalled
• Contactors: outdoor unit dead, no response to thermostat
• Condenser fan motors: fan won't spin, poor cooling/heating
• Reversing valves: heat mode fails, won't switch to cooling
• Control boards: error codes, unresponsive controls, defrost cycle stuck

Heat Pump Repair Questions & Answers

What's the most common heat pump repair?

The run capacitor is by far the #1 heat pump failure. This single part energizes both the compressor and condenser fan motor. When it fails, the outdoor unit stops working entirely — no cooling, no heating. You'll hear clicking from the disconnect box or the compressor trying to start but failing. A dual run capacitor (microfared rating matched to your model) is a $20 to $50 fix that restores full operation. Always confirm the µF rating and voltage rating before ordering.

How do I find my heat pump model number?

The model number is printed on the nameplate attached to the outdoor unit casing — usually a white or silver metal box near the compressor. Look for a label that starts with the brand name (, etc.) followed by alphanumeric characters. Write down the full model number; it tells you whether you need a Infinity board or a standard compressor. If the outdoor label is faded, check your HVAC paperwork or contact your original installer for the model.

Why does my heat pump keep going into defrost mode?

Defrost cycles are normal in winter — the unit removes frost from the outdoor coil every 30 to 90 minutes. But if it's cycling constantly or not switching out of defrost, the issue is usually the defrost control board, defrost thermostat, or the sensor that detects frost buildup. OEM defrost boards are model-specific and not interchangeable — always verify your exact model number before ordering.

Can I use aftermarket parts instead of OEM heat pump parts?

For basic parts like run capacitors and contactors, quality aftermarket options exist. But for sealed-system parts (compressor, reversing valve), control boards, and electronic sensors, OEM parts are a primary reliable choice. Aftermarket boards often don't communicate correctly with your thermostat, and non-OEM sealed-system parts create compatibility or performance problems and risk refrigerant leaks. Use Repair Clinic's heat pump parts lookup to confirm OEM compatibility before purchase.

Filter Heat Pump Parts by Your Model Number

Check the exterior nameplate on your heat pump's condenser, usually mounted on the cabinet near the compressor. If the label is not there, look inside the access panel or along the side of the cabinet. Record the complete model number, including letters, numbers, and any suffixes, rather than the serial number. Enter it in the model number search to pull up the parts matched to your unit. The model number filters the full heat pump parts catalog, not just one part category, so you can compare parts designed for your exact system. That means fewer wrong orders and a faster repair.