It’s always a good idea to know what kind of HVAC system you have. It can save you from embarrassing conversations and save you money on unnecessary service calls.

What’s the difference between an air conditioner and a heat pump?

So what makes an air conditioner different from a heat pump anyway? Not, much really.

In fact, and air conditioner is a kind of heat pump.

An air conditioner is a heat pump that only works in one direction though. It takes your indoor air, absorbs its heat, and then pumps it outdoors.

A heat pump, on the other hand, can pump heat in both directions. When people say “heat pump,” they are usually referring to a system that can pump heat outdoors and pump heat indoors. So basically, a heat pump is an air conditioner and a heater (an air conditioner that works in reverse), which takes heat from the outdoors and pumps it indoors.

While we can technically call an air conditioner a heat pump, that term is reserved for a system that can pump heat in both directions to provide heating and cooling. Click here if you want to know how a heat pump is able extract heat from the chilly air.

Do I have a heat pump or an air conditioner?

Here are some easy ways you can tell if you have a standard air conditioner or a heat pump that can pump heat outdoors and pump heat indoors:

1. Turn on Heat and See If Outdoor Unit (Condenser) is Running

Set your thermostat to heat and make sure warm is blowing through your vents. Then go outside to see if the outdoor condensing unit is on and making noise. This means that you have a heat pump that produces heat and not just an air conditioner. If you have a hybrid system (combines heat pump heating with gas furnace heating), turning on the heat may not always turn on the heat pump. You may need to continue your investigation.

2. Look for Brass Reversing Valve Inside of Condenser

Try looking through the top grill of your outdoor air conditioning unit. If you can see a piece of brass hardware, called a “reversing valve” similar to the image below, you have a heat pump. The reversing valve changes the direction of refrigerant flow to switch the heat pump from cooling to heating mode and vice versa. If you have a clear view and don’t see this brass piece, you most likely have an air conditioner. Sometimes, however, the reversing valve is hidden behind an access panel. Not seeing a reversing valve is not definitive proof that you have an air conditioner

3. Look for Label on Outdoor Unit (Condenser) and/or Indoor Air Handler

This last method does provide definitive proof. The last and most dependable way to check if you have a heat pump or air conditioner is to find the model number on your outdoor condenser unit and looking it up online. The model number should be near the top of the manufacturer’s sticker, located on the side of your outdoor unit. If you can’t find a label on the condenser unit, look for one on the side your indoor air handler.

M/N stands for Model Number, so simply write down the number and go inside and type it into Google. The search result will tell you all about your machine. Sometimes, the label clearly states what kind of unit you have. For instance, if you have “HP” at the beginning of the number, you know you have a heat pump.

Every heating and cooling system always comes with manufacturer and Energy Guide labels. Both labels will tell you what kind of system you have. You want to look for the Model Number on the manufacturer’s label. On the EnergyGuide label, look for SEER or HSPF. SEER, which stands for Seasonal Energy Efficiency Ratio is only used for air conditioners. If you have a heat pump, you will see a different energy efficiency rating acronym—HSPF (Heating Seasonal Performance Factor). Only heat pumps will have an HSPF rating.

If you have any questions about your A/C or heat pump, don’t hesitate to contact the heating and cooling experts at OnTime Service.


We service, repair, maintain, and install all makes and models of heating and coolings systems. Our experienced team of technicians will troubleshoot your home and give you straightforward pricing options.

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