How can I tell if I have a heat pump?

Why the outdoor unit looks the same either way

Trane, a heating and cooling manufacturer, says split system heat pumps and traditional central air conditioning (AC) units look virtually the same. Google's Nest help pages say heat pumps are typically located outside of the home and look like an air conditioner.

Carrier says both systems use refrigerant to transfer heat. Carrier says the key difference is that a heat pump has a reversing valve that changes the direction of refrigerant flow. That lets it pull heat from outdoor air and move it into the home during the heating season.

Carrier says an air conditioner cannot reverse this process. So it needs a separate heating system, such as a furnace. If you want the full comparison, see heat pump vs straight-cool air conditioner.

Check 1: the thermostat settings

Carrier calls the indoor thermostat the fastest way to find out. Bryant, another manufacturer, suggests cycling through the System or Mode settings. Look for a setting labeled Emergency Heat, Em Heat or Aux Heat. Trane says only a heat pump thermostat will have these settings.

Trane says auxiliary heat (Aux Heat) comes on when the heat pump needs help heating your home, and the thermostat signals the backup heating system. Trane says that backup might be electric heat strips in the air handler. It could also be a gas furnace in a dual-fuel system, which pairs a heat pump with a gas furnace.

Emergency heat (Em Heat) is a different setting. Trane says it comes on only if you manually make the switch. It shuts down the heat pump, and the backup heat becomes the main heat source.

Bryant says standard AC-only thermostats typically lack these controls. The word typically matters, so confirm with the label checks below. Auxiliary heat and emergency heat explain both settings in more detail.

Check 2: the labels on the outdoor unit

Trane suggests looking for a nameplate or sticker on the outdoor unit. It will likely be on the top or the side. Bryant says to find the Model Type or System Type field. It will often state Heat Pump or use the abbreviation HP.

If those words are not there, write down the brand and the model number. Trane says to search for the manufacturer name and model number online. The results will tell you if it is a heat pump or an AC unit. Trane also says to look through any owner's manuals the seller left behind.

Next, look for a yellow EnergyGuide label, a sticker that lists the unit's energy ratings. Trane says some manufacturers may have put this sticker on the inside unit or the outside unit. A previous owner may also have left the EnergyGuide card that came with the unit.

Trane says HSPF stands for heating seasonal performance factor, and SEER stands for seasonal energy efficiency ratio. Trane says both an AC unit and a heat pump will have a SEER or SEER2 rating. Only a heat pump will have an HSPF or HSPF2 rating listed.

Check 3: watch the outdoor unit in heat mode

Trane says to turn the thermostat to heat when it is not summertime, then go outside. If the outdoor unit kicks on, it is a heat pump. An AC unit will remain silent.

Carrier describes what you may notice. The fan in the outdoor unit is running and blowing cold air out the top while your house is being heated. A traditional furnace operates entirely indoors, Carrier says, so the outdoor AC unit stays silent in winter.

How common heat pumps are in Florida

The federal Energy Information Administration (EIA) ran its Residential Energy Consumption Survey for 2020. It estimated 8.06 million Florida homes, counting primary occupied housing units only. About 2.53 million used a central heat pump as their main heating equipment. About 2.65 million used a furnace.

The EIA also reported that Florida had the largest share of all-electric homes of any state in 2020. Trane notes that a home without a heat pump probably has a gas furnace, or possibly an electric furnace.

If it turns out you do have one, heat pumps in Florida covers what humidity and salt air mean for the system.

Why it matters once you know

ENERGY STAR, the federal energy efficiency program, gives heat pump owners specific advice. It says to make sure the heat pump is set to heat or cool. That avoids the system switching modes during unseasonably warm or cold days. It also says heat pumps do not save energy by turning the thermostat down when you are away or asleep.

Carrier says knowing you have a heat pump helps you avoid manually switching to Emergency Heat unless absolutely necessary. Google's Nest help says running emergency heat is usually expensive and inefficient. If you need it often, it says to have a local HVAC technician test your system.

Trane recommends professional heat pump maintenance visits each fall and each spring. Carrier says heat pumps run year-round and benefit from twice-yearly service.