The quickest way to identify your heating system

Look outside your home for a metal box about the size of an air conditioning unit. If you see one, you have a heat pump. If you don't see an outdoor unit and your heating comes from a cabinet inside your home — usually in a basement, attic, or closet — you have a furnace.

A heat pump moves heat from outside air (or ground) into your home. A furnace burns fuel or uses electricity to create heat directly. The outdoor unit is the giveaway: furnaces don't need one. If you're still unsure after checking outside, the details below will help you confirm.

Key Takeaways

  • Heat pumps have a visible outdoor unit that looks like an air conditioner; furnaces do not.
  • Furnaces are usually located inside your home in a basement, attic, or utility closet; heat pumps are split between indoor and outdoor components.
  • Your thermostat display or manual will label the system type, often showing "heat pump" or "furnace" in the settings or documentation.
  • Heat pumps are quieter and run year-round; furnaces cycle on and off and produce more noise when operating.
  • If you rent, your lease or landlord can tell you which system you have without you needing to investigate.

Check your thermostat settings and display

The easiest indoor confirmation is your thermostat. Look at the screen or the label on the wall unit. Many thermostats display the system type directly — you may see "heat pump," "furnace," or "heating system" listed in the settings menu or on the device itself.

If your thermostat has a mode selector, look for the options. A heat pump thermostat usually shows "Heat," "Cool," and "Auto" modes. A furnace thermostat typically shows "Heat" and "Cool" but no "Auto" mode that switches between them seamlessly. Some older furnace thermostats only show "Heat" or "Cool" depending on the season.

Check your thermostat's manual or the manufacturer's website if the label isn't clear. Search for your thermostat model number (usually printed on the device) plus "manual" to find documentation that names your heating system type.

Look at your indoor heating unit

Go to your basement, attic, or utility closet and locate your main heating equipment. A furnace is a large metal cabinet, usually rectangular or box-shaped, with ductwork attached. You'll see air vents coming out of it, and it may have a visible burner (if gas-fired) or heating elements (if electric). Furnaces are stationary and stay in one place year-round.

A heat pump's indoor unit is smaller and looks more like an air handler — a metal box with a fan inside. It's connected to refrigerant lines that run to the outdoor unit. The indoor component is less bulky than a furnace because it doesn't generate heat; it just moves it. If you see two connected units (one inside, one outside, linked by pipes), you have a heat pump.

Inspect the outdoor unit and refrigerant lines

Walk around the outside of your home and look for a metal cabinet about 2 to 3 feet tall and wide. This is the outdoor condenser unit of a heat pump. It will have a fan inside that you can sometimes hear running, especially during heating season. The unit is connected to your home by two copper or aluminum pipes that carry refrigerant.

If you see this outdoor unit, you have a heat pump. If your home has no outdoor unit at all, you have a furnace. Some homes have both an outdoor air conditioning unit and a furnace inside — in that case, the outdoor unit is for cooling only, and the furnace handles heating. Check whether the outdoor unit runs during winter (heat pump) or only during summer (air conditioner paired with a furnace).

Listen to how your system operates

Heat pumps run quietly and continuously, especially during cold weather. You may hear a soft humming from the outdoor unit or a gentle fan noise from inside. The system cycles on and off less noticeably than a furnace.

Furnaces produce louder noise when they cycle on — you'll hear a whoosh or rumble as the burner ignites (gas furnace) or heating elements set up (electric furnace). The sound is more pronounced and happens in distinct on-off cycles. If your heating system makes a loud bang or roar when it starts, you likely have a furnace.

During very cold weather, a heat pump may make a hissing or gurgling sound as it defrosts itself. This is normal and happens when frost builds up on the outdoor coils. A furnace does not make this sound.

Check your utility bills and heating costs

Heat pumps and furnaces have different operating costs and patterns. If you heat with a heat pump, your electric bill rises during winter months because the system runs on electricity year-round. If you have a gas furnace, you'll see a separate gas bill that spikes in winter, and your electric bill stays relatively flat.

If you heat with an electric furnace, your electric bill will spike in winter, but the pattern is different from a heat pump — the bill jumps sharply during the coldest weeks rather than rising gradually. Heat pump bills tend to climb steadily as outdoor temperatures drop.

Look at your past 12 months of bills. If you have both a gas bill and an electric bill, and the gas bill is highest in winter, you have a gas furnace. If only your electric bill rises in winter, you have either a heat pump or an electric furnace — use the other methods above to distinguish between them.

Ask your landlord, property manager, or previous owner

If you rent or just moved in, the fastest way to know is to ask. Your lease may list the heating system type. Your landlord or property manager can tell you when ready. If you bought the home, the home inspection report from your purchase should name the system. Check your closing documents or contact the inspector who wrote the report.

If you're buying a home and the listing doesn't specify, ask the seller's agent or request the information during the inspection period. This information is standard on any home inspection report.

Frequently Asked Questions

Can a home have both a heat pump and a furnace?

Yes. Some homes have a heat pump for heating and cooling, plus a furnace as a backup for very cold days. Others have a furnace for heating and a separate air conditioning unit (not a heat pump) for cooling. Check whether your outdoor unit runs in winter — if it does, it's a heat pump. If it only runs in summer, you have a furnace inside and an air conditioner outside.

What if I see an outdoor unit but I'm not sure it's connected to my heating?

Trace the refrigerant lines (the copper pipes) from the outdoor unit back to your home. They should enter through a wall or foundation and connect to your indoor unit. If the lines go to a wall-mounted indoor unit or a cabinet in your basement, it's part of your heating system. If they go to a different location, it may be a separate air conditioning system.

Does a heat pump have a furnace inside it?

No. A heat pump's indoor unit is an air handler, not a furnace. However, some heat pump systems include electric heating strips inside the air handler for backup on extremely cold days. These strips are not a furnace — they're just supplemental heating. The system is still called a heat pump.

Why does my heat pump sound like it's running all the time?

Heat pumps run more continuously than furnaces, especially in cold weather, because they move heat gradually rather than generating it in bursts. This is normal. The system is designed to run this way and is still energy-efficient. If the sound is very loud or unusual, contact a technician to check for problems.

If I have a furnace, do I need to worry about an outdoor unit later?

Not unless you add air conditioning. A furnace heats only and does not require an outdoor unit. If you want to cool your home, you would add a separate air conditioning unit (which looks like a heat pump's outdoor unit but only runs in summer) or replace your furnace with a heat pump system.