If you’re noticing a odor from your heat pump, it’s trying to tell you that something is up. We’ve put together a list of the top 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 moist evaporator coils or in the ductwork. This heat pump odor is often known as dirty sock syndrome. You can prevent this by scheduling frequent heat pump maintenance and air duct cleaning.

2. Heat Pump Smells Like Fish

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

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

Electrical problems are dangerous, so turn your heat pump system off immediately 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 utilize natural gas. If your heat pump smells like sulfur, a small animal may have creeped inside it for warmth and died. One of our Three Rivers Heating & Cooling experts can remove 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 in another place. If your heat pump smells like sewer, you might be dealing with a backed-up or broken sewer line. We recommend getting in touch with a company that does sewer line repair.

5. Heat Pump Smells Like Burning

You might be dealing with an electrical concern 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 problems in HVAC systems are dangerous and could lead to a fire. If you notice this smell, turn off your heat pump at the breaker and get a hold of us at .

6. Heat Pump Defrost Cycle Smells

Like we mentioned above, a dirty socks smell can happen when your evaporator coils need sanitizing. You might notice this smell when your heat pump is in defrost mode.

It’s typical for your heat pump to have to use defrost mode during heating season. When the air is much cooler, frost can form rapidly on the coils from condensation and interfere with heating. During defrost mode, your heat pump briefly switches to cooling to get rid of the frost.

Having a Three Rivers Heating & Cooling HVAC technician clean the coils will help get rid of the odor.

Trust Us with Your Heat Pump Repair Needs

It can be confusing to troubleshoot your heat pump by alone. Your comfort matters to us at Three Rivers Heating & Cooling, so you can count on our experts to support you when you need us. When you need heat pump repair in that you can count on, call us at .