Nest automatically activates Heat Pump Balance for homeowners who have a heat pump with auxiliary (AUX) heat and are connected to Wi-Fi (otherwise, you can use Early-On).

When you switch to cooling, Heat Pump Balance will no longer apply and you’ll have the option to use Early-On.

What is auxiliary (AUX) heat?

Heat pumps are super efficient compared to most other heating systems, but they take longer to heat your home the colder it gets outside. So heat pumps are sometimes paired with powerful AUX heat, which is much less efficient but turns on when the heat pump alone isn’t working fast enough.

Unfortunately, auxiliary heat costs two to five times as much as your normal heat pump and often comes on even when your heat pump could have gotten you efficiently to your target temp without auxiliary heat.

Other thermostats have one way to control auxiliary heat: the AUX lockout temperature. If your AUX lockout temp is 40ºF/4.4ºC, then auxiliary heat will come on when the room drops below 40ºF/4.4ºC.

With Heat Pump Balance, you don’t have to worry about the AUX lockout temp. Just choose whether you want more comfort or more savings, and Nest will adjust your lockout temp as needed.

How does Heat Pump Balance work?

Heat Pump Balance monitors how well your heat pump is working, the current weather, and the weather forecast. It uses this info to minimize how often expensive auxiliary heat is used and predict how to best use it in the future.

For example, Heat Pump Balance automatically turns the heat on early to give the heat pump enough time to get there without using AUX. So if your schedule says 70ºF/20ºC at 7pm, Heat Pump Balance will use Early-On technology to start heating at, say, 6pm. Because auxiliary heat is so expensive, running the heat pump longer is still cheaper than using AUX.

Heat Pump Balance gives you four options to choose from:

• Max Savings - This is the best setting for saving energy. In Max Savings mode, Nest gives the heat pump more time to get to your target temperature before turning on AUX and sets a lower AUX lockout temp.
• Balanced - This is the Goldilocks of the settings: it will give the heat pump more time to work, but will still turn AUX on quickly if it looks like you won’t get you to your target temperature on time. Balanced has an AUX lockout temp somewhere between Max Comfort and Max Savings.
• Max Comfort - When you choose Max Comfort, Nest will make sure you’ll get to the temperature you want, even if it means using auxiliary heat. Max Comfort is the default setting for Heat Pump Balance and generally gives you a higher AUX lockout temp.
• Off - You can also turn Heat Pump Balance off entirely and adjust your AUX lockout temperature yourself. The AUX lockout temperature can be changed in SETTINGS > EQUIPMENT > HEAT PUMP.

Keep in mind that no matter which setting you choose, how much AUX you use ultimately depends on the efficiency of your system. An efficient system won’t need to use AUX often, while an inefficient one may need to use AUX to keep your system heating even if you choose Max Savings.

But I was told that I shouldn’t turn the temperature down at night.

Some people will tell you that it's a bad, energy-wasting idea to set your bedtime temperature down if you have a heat pump. That advice only makes sense if you don't have Nest. With Heat Pump Balance, Nest can adjust the temperature while you sleep to keep energy bills low.

If you're a night owl, you'll sometimes see Nest display NIGHTTIME HEAT on its screen. When this happens, Nest has calculated that it can save energy by temporarily increasing the temperature in your home slightly while you sleep so it can get to your morning temperature using less (or even no) AUX heat.

So you can go ahead and turn down your nighttime temperature. Nest will just raise the temperature if needed to avoid using auxiliary heat.

How do I adjust my Heat Pump Balance settings?

Heat Pump Balance is enabled by default if you have a heat pump with auxiliary heat and your Nest is connected to the Internet. To change your comfort preference or to turn it off, go to Heat Pump Balance in settings:

• On your Nest Learning Thermostat, go to Settings > Nest Sense > Heat Pump Balance.

• On the Nest Mobile app, turn your device in landscape mode, then choose your thermostat and go to Settings > Nest Sense > Heat Pump Balance.

From there you’ll be able to choose from Off, Max Comfort, Balanced, and Max Savings.