Nest thermostats are becoming a household fixture as consumers have reported that they are extremely user-friendly, eco-friendly, and even budget-friendly! While we will learn a little more about Google’s Nest thermostat and everything it offers shortly, first you want to know: why does the Nest thermostat say “Aux Heat” and how can you turn it off?

If the Nest thermostat is displaying “Aux Heat” instead of simply “Heat” when you are warming your home, it probably means that it is extremely cold outside and your heat pump is using a secondary heating source in order to keep your space warm.

In this article, we are going to discuss how your heat pump works with your Nest thermostat, as well as how you can troubleshoot the Nest itself if that annoying “Aux Heat” display won’t go away. We want to make sure you understand everything there is to know (in one easy-to-read post) about the auxiliary heat your Nest is warning you about.

What Does Aux Heat Mean on Your Nest Thermostat?

One of the most beloved features of the Nest thermostat is that it actually knows what’s going on behind the scenes with your home heating and cooling system and will alert you via the Google Home app whether you need to change your air filter or if there is a serious problem that requires professional help.

When your Nest alerts you that your aux heat is in effect, it’s probably nothing to worry about, especially if you live in a cold climate. Here’s how it works:

  • Your heat pump is constantly taking cold air from outside and creating warm or even ht air to pump into your home.
  • If the temperature outside is less than 40 degrees Fahrenheit, it’s probably working pretty hard.
  • In fact, some ice build-up may form around the outside of your pump.
  • When this happens, your pump will need to switch to auxiliary heat while it simultaneously works as an air conditioner to pump heat from your house outside to de-ice the build up.
  • This aux heat can come from an electric resistance option or even a gas furnace.
  • While most heat pumps come with the electric resistance auxiliary heat, this response can become pretty expensive if it needs to be on for too long.

If you only see the au heat alert infrequently and for a short period of time when the weather gets especially cold, your heat pump is working correctly and there is nothing you need to do to turn it off.

However, if it stays on or turns on when it’s not freezing temperatures, you may have a problem. But don’t worry, we have a few troubleshooting solutions to help.

How to Turn off Aux Heat on Nest Thermostat

As you now know, you can easily control all aspects of your Nest thermostat through the Google Home app fr user convenience, and that includes turning off the aux heat with a few clicks!

Before you do, it’s important to remember that often the aux heat is a normal and useful tool that your heat pump is using to defrost and ensure your house continues to heat, even when it’s freezing cold. So you should only turn it off manually if you know it doesn’t need to be on, i.e. if it’s not cold outside of if it’s been on for more than 10 or 15 minutes.

If it’s time to turn it off yourself, here’s what you need to do:

  • Open your Google Home app.
  • Select the Nest thermostat.
  • Click “Settings”, “thermostat”, then “Emergency Heat.”
  • Select “OFF.”

Pretty simple right? Please remember that this is only to be used if there is no need for emergency or auxiliary heat, meaning it is not too cold outside.

It’s also important to turn this option back on after a day or so to ensure your pump doesn’t freeze during the next storm or especially cold day. 

If these directions did not work, and your Nest thermostat still says it’s working off “Aux Heat”, it’s probably time to contact Google support and get professional help.

Final Thoughts

While the aux heat capabilities on your thermostat are actually quite helpful in the long winter days, it shouldn’t be on for longer than several minutes. If it is, the electric resistance option that is running can cost you a fortune.

Now that you understand how, why, and when you should and can turn off your auxiliary heat on your Nest, you can avoid extreme energy bills and also keep your home toasty warm.

If you have any further questions or want to ensure you are turning off the aux heat at the right time, make sure you get in touch with the technicians at Google or even a professional electrician.