• Why does fan not run on outside unit


    Why is my fan not running on the outside?

    roxanne, frederick, MD

    Depending on the configuration of your heating system, the outdoor fan may or may not be called for. If you have a heat pump with electric backup, then the outdoor fan should always come on except when the outdoor unit is defrosting. If you have a heat pump with a gas or oil furnace backup, then the outdoor unit and fan will not run below a balance point temperature. The balance point is set often between 20 degrees and 30 degrees F outdoor temperature at which time the heat pump switches over to gas or oil furnace backup heat for heating in a dual fuel system. Or, if the unit is in defrost, it will turn off the outdoor fan. Contact a trained HVAC contractor, such as the ARS/Rescue Rooter branch in Laurel, MD at (301) 333-8888, to evaluate your system’s operation and determine if your system is working properly.