So how do you tell the difference between a heat pump and a regular AC unit? We’ll list several methods below. However, none of these methods are foolproof because the system might have been worked on or parts changed out. For instance the wrong thermostat might cause the system to misbehave. Check out the pictures below to begin the process.
Look for the Label. 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 above.
The air handler might also have a label saying “heat pump”. The air handler might be located in a closet or attic.
Look for the third service port. 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)
Look for the Reversing Valve. 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.
Look at the thermostat. 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.
Some digital thermostats also have an “emergency heat” switch. If you’re upgrading the thermostat yourself make sure you get the correct type for your system.
Go outside. The next method is to turn 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 then it still may be a heat pump depending on if it is on defrost cycle or not. However the defrost cycle will not engage until the system has been on a while. They will also cycle off when emergency heat is activated.
When to get service. If you have a heat pump and the compressor doesn’t run when the heat is on then it might not be set up correctly or a wrong thermostat was used. Call a HVAC technician.
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.
