How to Fix a Heat Pump: Quick Steps Every Homeowner Can Use

If your heat pump stopped heating or cooling, you don’t have to panic. Most problems are easy to spot and fix with a few tools and a bit of patience. Below, we walk through the most common issues, how to test them, and simple repairs you can do yourself.

Check Power and Thermostat Settings First

The quickest thing to verify is whether the unit is actually getting power. Open the breaker box and look for any tripped switches. Reset any that have flipped and make sure the indoor thermostat is set to the correct mode – heat for winter, cool for summer. If the thermostat shows an error code, consult the manual; many codes point to simple sensor problems.

Next, inspect the outdoor unit’s disconnect box. A loose wire or a blown fuse can stop the pump dead in its tracks. Re‑tighten any loose connections and replace a fuse if you have the right rating. Once power is confirmed, move on to the next steps.

Clean the Coils and Examine the Fan

Dust and debris build up on the outdoor coils, choking airflow and forcing the pump to work harder. Turn off the power, then gently brush off the fins with a soft brush or use a garden hose on low pressure. Be careful not to bend the fins – they’re fragile.

While you’re there, check the fan motor. Spin the fan blade by hand; it should turn freely. If it feels gritty or sticks, the motor bearings may need lubrication or the motor could be failing. A humming sound without blade movement usually means the motor’s stuck – in that case, you can try a short reset by turning the power off for a minute, then turning it back on.

Another common culprit is the outdoor fan capacitor. A swollen or leaking capacitor won’t give the fan enough boost, resulting in poor airflow. Replacing a capacitor is inexpensive and can be done with a screwdriver and a few safety gloves. Make sure you match the voltage rating printed on the old part.

Inspect Refrigerant Levels and Leaks

Low refrigerant can make the pump feel like it’s not heating at all. While most homeowners should leave refrigerant handling to a licensed tech, you can look for obvious signs of a leak. Check the copper lines for oily residue or frost buildup. If you see either, call a professional – refrigerant leaks require proper recovery and refill.

Sometimes the problem isn’t the refrigerant itself but a blocked or frozen filter dryer. Locate the dryer (usually near the indoor coil) and look for ice. Let the unit defrost completely before restarting.

When to Call a Pro

If you’ve checked power, cleaned the coils, verified the fan moves freely, and still have no heat or cool, the issue may be deeper. Faulty compressors, serious refrigerant leaks, or electronic control board failures need a certified HVAC technician. Trying to repair these yourself can void warranties and be unsafe.

Before you call, note any error codes, unusual noises, or smells. This info helps the technician diagnose the problem faster and can save you time and money.

Fixing a heat pump doesn’t always require a big expense. By tackling the easy checks first, you’ll often get your system running again without a service call. Keep a basic maintenance schedule – clean the coils each season, change filters regularly, and watch for warning signs. Your heat pump will thank you with years of reliable comfort.