Heat Pump Keeps Cycling Off And On? Repair It With These Tips

If your heat pump cycles off and on every few minutes, there may be a problem with the dual start capacitor. The capacitor gives the heat pump extra power when it first comes on, runs into electrical problems, or needs to push through extreme weather conditions, such as unexpected cold spells. Sometimes, the capacitor can develop rust and break down. If any of the issues occur, the heat pump no longer has the extra power boost it needs to stay operational. You can troubleshoot and fix the problem with the tips below.

Access and Examine the Capacitor

The first thing you must do is disconnect power to the heat pump at the unit's pullout electrical box. The box connects directly behind the heat pump on the side of the home. Now, the next step in your repairs is to remove the paneling from the heat pump to access the capacitor. The paneling usually sits in the right or left corner in the back of the unit. It's a good idea that you use a manual screwdriver to loosen up the screws instead of an electric screwdriver. You don't want to accidentally strip the screws, or else you may need to replace the entire panel.

Now, look for the capacitor. The capacitor has a round top covered with three prongs and looks similar to a large soda can. This type of capacitor uses four colorful wires to connect to the heat pump and powers the appliance's motor and compressor.

One of the things you want to do is examine the capacitor for rust to see if you need to replace it. A rusted capacitor can potentially create power fluctuations in your heat pump, which may be one of the reasons it cycles off and on regularly. The rust can penetrate the housing and spread to the internal parts and wires of the capacitor.

Eventually, the rust travels to the main parts inside the heat pump, such as the compressor and motor. If the motor or compressor goes out, the heat pump won't work at all. It's a good idea that you replace the capacitor to prevent this major repair problem.

Replace the Capacitor

To replace the rusted capacitor, purchase a replacement dual start capacitor from your local HVAC store. You can obtain the right make and model of the part by copying down the product information listed on the capacitor's housing. It's not a good idea to remove the old capacitor from its holder, because you'll need to use it as a guide during the replacement.

Once you have the right part, follow the instructions below:

  1. Disconnect the colored wires from the capacitor one wire at a time, then connect it to the new capacitor.  
  2. Use a soft rag to wipe away any dirt or smudges you find on the new capacitor. These things can eventually clog up the connectors on the capacitor.
  3. Place the capacitor back in its holder, then turn back on the heat pump's power. 
  4. Wait 15 minutes for the heat pump to reach the temperature set on your thermostat.

If the heat pump reaches the right temperature and only cycles off and on when the thermostat rises above the temperature, you fixed the issue. If the heat pump continues to cycle off and on as it did before you made the repairs, contact a heating and cooling contractor for services. The rust on your old capacitor may have spread to the compressor, which require the expertise of a specialist.

For more information about your heat pump, or to find out why it cycles off and on every few minutes, schedule an appointment with your HVAC today. Click for more information.