In my condo I have a heat pump with electric strips for auxiliary heat. When the outdoor temperature is quite cold, the heat never turns off. It reaches the set temperature, but keeps running.

When this happens, the aux heat turns on and off repeatedly. It seems like the same situation described here:

Question: Can anyone recommend a solution that allows adjusting the behavior of the aux heat (E.G. a separate CPH setting for the aux heat), so that the aux heat stays on longer.

  • How many stages of aux heat does your air handler support? Dec 26, 2020 at 22:34
  • It sounds like you're looking for a product recommendation, and that is, unfortunately, off-topic.
    – FreeMan
    Dec 26, 2020 at 23:08
  • Please use the edit button to provide a more detailed description of the primary heat source and the aux heat source, how they interact and how they are controlled .
    – Alaska Man
    Dec 26, 2020 at 23:53

1 Answer 1


When you have a heat pump the thermostat that controls it is a 2 stage thermostat. The first stage controls the heat pump and the second stage controls the heat strips. The heat pump operates off the first stage and if it can not produce enough heat and the indoor temperature falls below the thermostats set point by a certain amount the second stage energizes the heat strips. The heat pump will usually operate constantly and the heat strips will cycle on and off on the second stage part of the thermostat. There are a few different ways these units can operate depending upon the thermostat, unit and the wiring of these systems. Yours is probably the way I described. If you want to change the way the heat strips operate contact an HVAC contractor in your area and ask what your options are. Hope this helps

  • Along with this answer there are dead band or span settings in most electronic thermostats the control may be set higher than the set point to reduce cycling. The aux heat or emergency heat is probably producing most of the heat when the system gets within a target the aux drops out if the set point is not met the aux kicks back in this is easier on the compressor and consumes less power than starting and stopping.
    – Ed Beal
    Dec 27, 2020 at 15:44

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