Video · Furnaces and Heating
Furnace Part Replacement That Isn't a Furnace: New Heat Strips
If your indoor unit runs on electricity with a heat pump outside, it's an air handler, not a furnace. Its backup heat comes from electric heat strips, and when they fail, cold snaps get cold fast.
Job footageSwiftPro
- Topic
- Furnaces and Heating
- Length
- 0:31
- Posted
- August 3, 2026
- Shot by
- The SwiftPro crew, Northern Virginia
What you’re seeing in this video
A young tech in a navy work jacket works inside an open air handler in a utility room, wiring in a new electric heat strip kit. The boxed heating elements sit on the floor next to him, and he drives the screws home with a cordless tool.
Heat strips are coils of resistance wire, a lot like a toaster's, that slide into the air handler where the blower air passes over them. The sound of that tool is the fix that turns the heat back on.
Why it matters in your house
- Heat strips back up a heat pump on the coldest days and during defrost. If the house falls behind in a freeze or the air feels lukewarm, a failed strip, sequencer or limit is a common cause.
- Emergency heat on the thermostat runs the strips alone. It works, but it's the most expensive way to heat the house, so treat it as a stopgap until a tech checks the heat pump.
- A burning dust smell the first time the strips run each fall is normal. A sharp electrical smell, or a breaker that keeps tripping, means shut it off and call.
How do I know if my heat strips are bad?
Switch the thermostat to emergency heat and give it ten minutes. If the air from the vents stays cool, the strips or their controls likely aren't working. A tech checks the elements, the sequencers or relays, the limit switches and the breaker with a meter, since any one of those can keep a good strip from heating.
Want it done at your place? See Furnaces and Heating at SwiftPro or call (703) 997-9757.
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