What is a Defrost Cycle?

The Defrost Cycle

Have you ever heard of the term “defrost cycle”?

Maybe you’ve never heard that term before and feel even more clueless. The good news is that either way, we can help break it down for you.

The short answer is that the defrost cycle keeps any ice or frost off your heat pump coils in cold temperatures so the unit can continue to run efficiently. This also helps prevent any ice damage to the equipment.

The more “technical” answer is that during a typical heat cycle, your heat pump extracts heat from the air outside and uses refrigerant to transfer it inside to warm it. When outdoor temperatures drop, the moisture in the air freezes along with the coils which, when not addressed, can reduce efficiency, and eventually cause some serious damage.

How does the heat pump “know” when to go into defrost?

There is actually a timer built into the unit that controls how often the unit goes into a defrost cycle.

When outdoor temperatures reach about 30 -20 degrees Fahrenheit (depending on your unit), the defrost cycles will automatically occur in 30-, 60-, or 90-minute increments.

How to Know if a Heat Pump is Defrosting Properly

The first indicator is whether or not the outside unit has frost or ice buildup on the coils. If there is none, it’s probably working just as intended! You will know the unit is actively in defrost if the indoor fan stops. The outdoor fan will also stop at this point. The unit will stop heating, but you will hear the outdoor compressor running.

Oftentimes this can sound like a jet taking off or, my favorite description I’ve heard from a customer, a dying moose.

Believe it or not – this is all normal.

However, if you believe your unit is going into defrost too often, not enough, or not at all and ice is present – please don’t hesitate to give us a call! We provide service 24/7.

We also have a YouTube video that you can watch by clicking here. Feel free to comment on any other tips, tricks, or information you would like to learn about!