6 Common Heat Pump Smells Explained

September 30, 2021

If you’re noticing a smell from your heat pump, it’s attempting to tell you that something is wrong. We’ve put together a list of the most common six heat pump smells, what causes them and how you can fix 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 probably mold growing on wet evaporator coils or in the ductwork. This heat pump odor is often referred to as dirty sock syndrome. You can prevent 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 problem

Electrical problems are dangerous, so shut your heat pump system off right away at the breaker box and call us at 928-639-4251 for heat pump repair.

3. Heat Pump Smells Like Sulfur

Usually when you are dealing with a rotten egg smell, you have a gas leak. But your heat pump doesn’t run on natural gas. If your heat pump smells like sulfur, a small animal may have crawled inside it for warmth and died. One of our Connolly Electric & Mechanical [techs can get rid of the smell by cleaning your heat pump.

4. Heat Pump Smells Like Sewer

As we discussed earlier, your heat pump is electric, so any rotten egg smells are tied to a gas leak somewhere else. 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 have an electrical problem if your heat pump smells like burning, burning plastic or burning rubber. This burning smell can be caused by melting plastic on electrical wires. Electrical issues in HVAC systems are dangerous and could lead to a fire. If you notice this smell, shut off your heat pump at the breaker and call us at 928-639-4251.

6. Heat Pump Defrost Cycle Smells

Like we talked about previously, a dirty socks smell can happen when your evaporator coils need cleaning. You might notice this smell when your heat pump goes into defrost mode.

It’s common for your heat pump to have to turn on defrost mode during heating season. When the air is much cooler, frost can form fast on the coils from condensation and impede heating. During defrost mode, your heat pump temporarily switches to air conditioning to remove the frost.

Having a Connolly Electric & Mechanical HVAC technician clean the coils will help eliminate the smell.

Trust Us with Your Heat Pump Repair Needs

It can be difficult to troubleshoot your heat pump by yourself. Your comfort matters to us at Connolly Electric & Mechanical, so you can count on our professionals to assist you when you need us. When you need heat pump repair in Cottonwood that you can depend on, call us at 928-639-4251.