How do I know if I have a heat pump?

Submitted by Ray Thornburg on Mon, 09/03/2012 - 12:29

How do you tell the difference between a heat pump and a regular AC unit?

The first thing to understand is that any of these methods listed below are not foolproof. This is because parts can be easily switched between  different systems and systems can be repaired in any number of different ways. For instance a thermostat or compressor can be changed out during repair process.

  • This first method is to simply look for the words Heat Pump on the compressor ( the noisy thing outside). Since heat pumps require a reversing valve which is installed at the factory the compressor unit will usually (not always) have a label like the one below.

  • The next method is to look for the third service port near where the refrigerant lines enter the enclosure. This third port is only on heat pumps and it is usually sticking out of the enclosure above the refrigerant lines.(but not always)

heat pump third port






  • The next method is to look for the reversing valve inside the compressor enclosure. A reversing valve is a 2" diameter tube about 6" long with four copper pipes coming out of it. You can look through the top where the fan is to see if it is there. Sometimes it's hidden behind a panel though.


    Reversing Valve





reversing valve

    It can be difficult to peep into the compressor cabinet to find the reversing valve.






  • The next method is to look at your thermostat. If it has a separate setting for emergency heat it might be a heat pump. The reason for this setting is that heat pumps are usually used in milder climates where it doesn't get real cold often so they are usually built with electric heat strips for those cold days. This method isn't always reliable because the thermostat may not be hooked up correctly or may have been switched.


heat pump thermostat






  • The next method is to cut your heat on and go outside and see if your compressor is running. If it is then it's a heat pump. If it isn't it still may be a heat pump depending on if it is on defrost cycle or not. They will also cycle off when emergency heat is activated.
  • The air handler might have a label too. The air handler might be in a closet or in the attic.


air handler label







In the right climate heat pumps can save you cash on your energy bill. They work in a similar  way that an air conditioner does except in reverse. An air conditioner takes heat energy inside the home and transfers it outside and a heat pump reverses this procedure.

If you live in the Charleston area give Blue Palmetto Home Inspection a call. We always have time for you! 843-608-5851

Submitted by Ray Thornburg on Mon, 09/03/2012 - 12:29