If you’re discovering a smell from your heat pump, it’s attempting to tell you that something is up. We’ve put together a list of the most common six heat pump smells, what causes them and how you can repair them.

  1. Heat pump smells musty
  2. Heat pump smells like fish
  3. Heat pump smells like sulfur
  4. Heat pump smells like sewer
  5. Heat pump smells like burning
  6. Heat pump defrost cycle smells

1. Heat Pump Smells Musty

If your heat pump smells musty, there’s likely mold growing on wet evaporator coils or in the ductwork. This heat pump odor is often referred to as dirty sock syndrome. You can deter this by scheduling regular heat pump maintenance and air duct cleaning.

2. Heat Pump Smells Like Fish

If your heat pump smells like fish, there could be a couple of things wrong:

  • Overheated motor
  • Wiring issue
  • Plastic components or coating is melting
  • Other mechanical difficulties

Electrical problems are unsafe, so turn your heat pump system off as soon as possible at the breaker box and contact us at for heat pump repair.

3. Heat Pump Smells Like Sulfur

Normally when you have a rotten egg smell, you’ve got a gas leak. But your heat pump doesn’t use natural gas. If your heat pump smells like sulfur, a little animal may have creeped inside it for warmth and died. One of our Phelps Heating & Cooling, Inc. technicians can eliminate the smell by cleaning your heat pump.

4. Heat Pump Smells Like Sewer

As we reviewed above, your heat pump is electric, so any rotten egg smells are linked to a gas leak elsewhere. If your heat pump smells like sewer, you might be dealing with a backed-up or broken sewer line. We recommend contacting a company that does sewer line repair.

5. Heat Pump Smells Like Burning

You might be dealing with an electrical problem if your heat pump smells like burning, burning plastic or burning rubber. This burning smell can be the result of melting plastic on electrical wires. Electrical issues in HVAC systems are serious and could cause a fire. If you notice this smell, turn off your heat pump at the breaker and contact us at .

6. Heat Pump Defrost Cycle Smells

Like we mentioned earlier, a dirty socks smell can happen when your evaporator coils need to be cleaned. You might experience this smell when your heat pump has defrost mode.

It’s ordinary for your heat pump to have to switch on defrost mode during heating season. When the air is much colder, frost can form rapidly on the coils from condensation and impede heating. During defrost mode, your heat pump temporarily switches to air conditioning to clear away the frost.

Having a Phelps Heating & Cooling, Inc. HVAC technician clean the coils will help eliminate the odor.

Trust Us with Your Heat Pump Repair Needs

It can be confusing to troubleshoot your heat pump by all by yourself. Your comfort matters to us at Phelps Heating & Cooling, Inc., so you can count on our specialists to assist you when you need us. When you need heat pump repair in that you can depend on, call us at .