How Do I Know If I Have a Heat Pump or an AC?

Heat pumps and standard air conditioners look nearly identical on the outside, making it difficult to tell which system you have at a glance.

That said, with a bit of detective work, you can quickly determine which system you have.

In this blog, we’ll share 4 simple methods to determine whether you have a heat pump or a standard AC system:

Let’s look at each of these methods in more detail below.

If your thermostat has an emergency heat setting, you have a heat pump instead of a standard AC.

You see, the emergency heat setting is unique to heat pumps. It gives you the ability to switch to your backup heating source (such as a gas furnace) if the heat pump stops working.

Do this: Go to your thermostat and look for a button labeled “EM,” “EMER,” or “EMERGENCY” heat (pictured below). If you have a digital thermostat, these abbreviations may appear on the screen.

Can’t find the emergency heat button on your thermostat or the display? Try Method #2 to verify if you have a heat pump or standard AC.

While you’re at the thermostat, turn it to HEAT mode and then check to see if the outdoor unit turns on. If the outdoor unit turns on, you have a heat pump instead of a standard AC unit.

We’ll explain.

Heat pumps use the outdoor unit to absorb heat from the outside air and transfer it into your home. Meaning that if you have a heat pump, you should hear the outdoor unit turn on after you switch the thermostat to HEAT.

Other heating systems, such as a furnace, do not use the outdoor AC unit at all to heat your home. So if you have a heating system other than a heat pump, the outdoor unit will not turn on at all in heating mode.

Do this: Turn your thermostat to HEAT, and wait until you feel warm air coming out of the vents. Then walk outside to the outdoor unit and listen if it is running. If the outdoor unit is running, you have a heat pump.

If you suspect your outdoor unit is malfunctioning, you can use the following methods to determine whether you have a heat pump or standard AC system.

On the side panels of the outdoor unit, you’ll see a manufacturer and/or EnergyGuide label. These labels often have information that can conveniently help you determine whether or not you have a heat pump.

The manufacturer label includes the specifications of the system. Sometimes, this label will clearly state that the unit is a heat pump, or the model number will have an “HP” at the beginning, which indicates the system is a heat pump.

You can also look for the bright yellow EnergyGuide label on the outdoor unit. If you see two numbers, one for a “SEER” (Seasonal Energy Efficiency Ratio) and one for an “HSPF” (Heating Seasonal Performance Factor), then you have a heat pump.

Since heat pumps provide both cooling and heating, they use both SEER ratings for how efficiently they cool and HSPF ratings for how efficiently they heat.

Do this: Go to the outdoor unit and try to find the information on the labels explained above. If you can’t find any information that tells you what kind of system you have, write down the model number and search for it online. You should be able to tell whether your unit is a heat pump or standard air conditioner by looking on the manufacturer’s website.

Can’t locate the labels or read them because they’ve faded? No worries! This last method will help you for sure.

Finally, you can look inside the outdoor unit to see if it has a reversing valve.

The reversing valve is unique to heat pumps. It is the part that reverses the flow of refrigerant in the system, which allows the heat pump to switch from cooling to heating mode.

If you can see a reversing valve inside the outdoor unit, then you have a heat pump.

Do this: Make sure to turn off the system so that the outdoor fan is not spinning. Then peek inside the top of the outdoor unit and look for a brass-looking device with three fittings on one side. The device is the reversing valve. If you see this valve, you have a heat pump; you have a standard air conditioner if you don’t see it.