Heat Pump Indoor Fan Runs Continuously

Heat Pump Indoor Fan Runs Continuously – Richard, my indoor fan motor, on the heat setting, runs constantly and won’t cut off unless I lower thermostat by 2° F. It is sometimes annoying for me to constantly change the setting just to get it to shut down plus trying to maintain a comfortable temperature without the fan running all the time. What could the problem be and is it something I can fix myself or do I need to call in a service company to make the repair? Thank for your help!!

Heat Pump Indoor Fan Runs Continuously

This sounds to me like the heat pump is running off the auxiliary or emergency heat and something is wrong with your heat pump condenser producing heat. 2° F is usually the minimum you want in the heat pump thermostat offset before the auxiliary heat kicks in to help the heat pump condenser keep up when the weather is colder outside. Most thermostat offsets for heat pumps between the condenser heat and the auxiliary heat is 3° F or more. 

Heat Pump Heat - Heat by Refrigeration or Auxiliary Heat?

Most air source heat pumps have two different types of heat. One uses the process of refrigeration to provide heating and with all heat pumps this is your primary and most efficient way of heating for a heat pump.  The secondary or auxiliary method of providing heat for an air source heat pump is typically electric heating. Although there are other methods for providing secondary heat electric heating for air source heat pumps is the most common. 

When the temperature is really cold or the system has a difficult time of keeping up with heat loss the heat pump thermostat usually will lose ground. The temperature will continue to fall on the thermostat. To help the refrigeration part of the heat pump keep up the thermostat has an offset. Yours happens to be ~2° F which is the offset temperature. This can be changed in the thermostat program to 3 or 4° F. See the thermostat set up guide to change this setting. 

Heat Pump Condenser Problem

When the refrigeration part of the heat pump has a problem the auxiliary heating will kick when the offset temperature is achieved. So if you have the thermostat set for 70° F and the temperature falls to 68° F then the auxiliary heating kicks in to assist the condenser or refrigeration part of the heat pump system. If there is something wrong with the condenser providing heat then the auxiliary heating will be the primart source of heating for your system. In this case you need to chack a few things:

  1. Check to make sure the heat pump condenser (outside) is running. If it is not then check the breakers and fuses in the system. If a breaker is tripped for the heat pump then reset it. If it trips again then you need to call for service.
  2. If the heat pump condenser is running you can touch the refrigeration lines going to the condenser. Be careful, if it working properly these lines can be very hot. If these lines are cold (in heating mode) then you likely have a problem with the refrigeration portion of the heat pump system and need to call for service and repair. 
  3. It could also be a control problem which will definitely need the services of an HVAC repair contractor.

Heat Pump Indoor Fan Runs Continuously - Conclusion

Furthermore, always make sure you get regular HVAC service for a heat pumps system. It is recommended that you have a professional HVAC company chack out your heat pump system 2 times a year for preventative maintenance. Once in the Spring, before the cooling season, and once in the Fall, before the heating season. By doing so, you can avoid many common problems that can occur during the year. Plus, small things can be repair before they become big problems for your heat pump. 

Regular heat pump maintenance does not guarantee you will not have any failures during the year, but it can prevent problems before they occur. Electrical systems and mechanical systems can be looked at with a close trained eye. A determination can be made if something simple needs to be replaced. Something that could possible lead to failure. Also, using instruments, a technician can make sure things are operating normally. This gives you peace of mind by letting you know your system is operating normally. Good luck!!

To learn more about heating systems and HVAC use this resource.

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