Understanding the Defrost Feature of Your Heat Pump

What is the Defrost Mode On Your Heat Pump?

Winter is here, and with it comes the challenge of keeping our homes warm and comfortable. If you’ve ever felt like your heat pump just can’t keep up with the cold, you’re not alone. Many homeowners misunderstand the defrost mode on their heat pump, seeing it as a problem rather than an essential function.

Why Does My Heat Pump Need a Defrost Mode?Β 

Imagine waking up to a freezing home because your heat pump can’t handle the cold. That’s a nightmare for anyone! Defrost mode activates when outdoor temperatures drop significantly, causing moisture in the air to freeze on the outdoor coil. Without this mode, ice would quickly build up, blocking airflow, reducing efficiency, and potentially damaging your heat pump unit. Instead of seeing the defrost cycle as a hassle, think of it as your heat pump’s self-care routine.

How does the Defrost Cycle Work?

All heat pumps are designed to defrost in cold weather to keep them running efficiently. This usually happens in the early morning and evening when heating demand is highest. During defrost mode, you’ll notice that the indoor fan stops while the outdoor unit heats up to melt the ice on the coil. This process typically lasts 10-15 minutes, after which the unit resumes heating. Depending on the temperature and moisture in the air, condensation may form and freeze again, prompting another defrost cycle.

To maintain proper function, avoid turning off the outdoor power supply isolator during defrostingβ€”interrupting the cycle can cause more ice buildup and disrupt the heating process. Also, undersized units may need to defrost more frequently, as they struggle to reach set temperatures in extremely low ambient conditions. Properly sized heat pump units have shorter compressor run times and operate at lower speeds, which can help reduce the need for defrosting.

Signs Your Heat Pump is in Defrost Mode

You might panic when your heat pump stops heating momentarily, but this is a normal part of the defrost cycle. Here’s what to look for:

  • Indoor and outdoor fans will pause.
  • The compressor keeps running, sometimes louder than usual.
  • Steam or β€œsmoke” may appear from the outdoor unit (don’t worry, this is just steam).

These signs indicate that your heat pump is working to melt the ice and restore optimal performance.

Tips to Keep Your Home Warm During the Defrost Cycle

Feeling the chill when your heat pump goes into defrost mode? Here’s how to stay cozy:

  • Set Timers: Program your heat pump to start heating an hour or two before you wake up or return home.
  • Night Settings: Run your heat pump at a lower temperature (18-19Β°C) overnight to maintain warmth without overloading the system.
  • Regular Maintenance: Clean your heat pump filters and make sure the outdoor unit is clear of debris to reduce the frequency of defrost cycles. Ensure sufficient airflow, keep coils and filters clean, and raise the outdoor unit 100mm above ground if possible to allow proper drainage.

Additional Tips for Defrost Efficiency

For the best performance,Β select a heat pumpΒ sized for the average lowest winter temperatures in your area. A properly sized unit will need to defrost less often, helping maintain steady warmth. Lastly, ensure high-quality installation, avoiding pipe kinks and refrigerant leaks that can affect defrost efficiency.

Need to Service or Upgrade Your Heat Pump? Fill out the form below or visit our HVAC Solutions Page to learn more of what we can offer you.

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Amanda Beatson
01:11 16 Sep 25
We have used Superheat Electrical for heat pump and SmartVent installation, as well as general electrical work. For all the jobs they have been reliable and the work has been excellent. Communication from the office and the team is awesome. Would definitely chose them again and recommend to others.
Vee Osborn
02:37 29 Aug 25
When my gas heater kicked the bucket I decided to install 2 heatpumps. I got 4 quotes in all and decided to go with Superheat Electrical due to their competitive pricing and excellent communication.
The team were very professional and respectful throughout all my interactions. Their work was completed in a timely manner and to a high standard.
100% recommend Paul, Kristine and the Superheat team!!
Merekara Warrington
00:31 14 Aug 25
Such a great team to work with! My husband was recommended this company and they were by far the best in all aspects - communication and site visit was timely and pleasant; quote was within our budget; post-quote follow-up was also pleasant - Kristine was so lovely and understanding as we were waiting for ANZ approval for the Good Energy loan top-up regardless of this once it was approved, the team were quick in securing an install day; the team showed up early on the day for install and took just one day to complete. They did a tidy good job of it and cleaned up after themselves. Following installation, Kristine also made contact to follow-up with us and make sure the system was running well and if were happy with it. Overall would happily recommend this business to others! Great people and a great product! Our family are comfortably warm or cool when needed πŸ™‚
Jan Kayla Mendez
07:10 29 Jul 25
Highly recommend! So happy with our new heat pump!

We just had a heat pump installed, and the whole experience was smooth and efficient. From the first consult, Paul was knowledgeable, professional and helpful to explain what would work best for our space and budget.

The installation was great too. Everything was done on time and the team were friendly, respectful of our home and left the area spotless, as if they were never there!

If you’re thinking about getting a heat pump, I’d totally recommend going with Superheat. Outstanding customer service, quality products and expert workmanship. We’re so happy with the result! 😊
Graham Caunter
22:40 28 Jul 25
Wow, made an appointment & they were there within a day. Thank you. Had our HRV filters changed.
Sam Vaka
03:42 16 Jul 25
Great customer service and easy to connect with.
Grace Bassett
00:13 16 Jul 25
Had our heatpump installed, excellent service, took all the cardboard away when finished. Very happy, highly recommended.
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