Is Your Ecobee Auxiliary Heat Running Too Long?

Brigid Levi
by Brigid Levi

Heater season is upon us! If you have an Ecobee thermostat, you may notice an alert pop up after running the heater for a few weeks: “Aux heat running too long.” It should be noted that “Aux” stands for auxiliary, a secondary heating system. Once the temperature outside reaches a certain low point, your compressor switches over to auxiliary heat.

If you receive this message, there are a few things you can check on your Ecobee.

If your Ecobee auxiliary heat is running too long, check the aux heat threshold setting. Increase the value so the auxiliary heat takes longer to kick on. Another option is to set a minimum runtime for the compressor or the auxiliary heat. Finally, you can turn off the alerts or reset your thermostat.

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What is Auxiliary Heat?

If your regular heater isn’t sufficient enough to meet the indoor temperature settings, auxiliary heat takes over. If you live in a particularly cold area, your heat pump may need to rely on the aux heat to properly warm your home.

Aux heat systems can be oil-based heating units, natural gas furnaces, or electric resistance systems.

It can be very expensive to run your aux heat. Ecobee alerts you if the auxiliary heat has been running for a long period so you are aware of the expense.

Compressor Outdoor Temperature Thresholds

Ecobee sets the minimum compressor outdoor temperature to 35°F by default. If the outside temperature goes below this number, the compressor won’t run. Instead, the auxiliary heat kicks on to continue heating your home.

Before changing this setting, check with your heat pump manufacturer for the lowest temperature at which your pump can safely run. The equipment may become damaged if you run it at temperatures below what it can handle.

Increase Auxiliary Heat Threshold

It’s possible to change the auxiliary heat threshold so it won’t kick on until absolutely necessary. You can view how your HVAC system runs by checking the Home IQ information on the thermostat’s web portal. Here, you’ll be able to see when your aux heat has kicked on.

After determining the lowest temperature at which your pump can safely run, change the aux heat threshold so it activates only when necessary. Note that your heat pump’s efficiency reduces as the outside temp lowers.

To change the aux heat threshold, open the Ecobee app. Go to Settings > Installation Settings > Thresholds > Select “Manually” and enter the value you determined with the Home IQ info.

You can also set a maximum outdoor temperature threshold. This prevents the aux heat from running past a certain outdoor temperature. For example, setting the maximum outdoor temperature to 40°F means your auxiliary heat won’t kick on if the temperature goes above 40°F.

Auxiliary Heat Runtime

You can choose a certain length of time you want the aux heat to run. This is a good option if you have an expensive aux heat system.

Ecobee sets this time to five minutes by default. Meaning, your aux heat will run for a period of five minutes before shutting off. You can change the minimum run time to whatever you wish to save on electricity or oil bills.

To change the threshold, go to the web portal. Then go to Settings > Installation Settings > Thresholds > Minimum Time. Choose the minimum runtime here. To prevent short cycling, Ecobee recommends you keep the minimum time to less than 300 seconds.

Compressor to Auxiliary Runtime

In addition to choosing the runtime of your auxiliary heat, you can set a minimum runtime for your compressor. This forces the compressor to run a certain length of time before the HVAC system switches to auxiliary heat.

If you’re getting too many alert messages, your compressor is automatically switching to aux heat as soon as it turns on. To change the compressor runtime go to the web portal. Then go to Settings > Installation Settings > Thresholds > Compressor to Aux Runtime. Set the compressor runtime here.

Compressor to Auxiliary Temperature Delta

This configuration allows you to select a minimum difference in degrees between your current indoor temperature and the temperature threshold for the aux heat. By default, this is set to auto. So, the delta changes based on your Home IQ info.

If you get too many alerts, you can change the difference in degrees to whatever works best for you. Start at the web portal. Then go to Settings > Installation Settings > Thresholds > Compressor to Aux Temperature Delta. Change the value here.

Video: The Right Ecobee Heat Pump Settings

Turn Off Aux Heat Running Alerts

You have the option to turn off the aux heat alerts, though it is nice to see why and when your heating bill fluctuates. You can turn off these alerts either on the web portal or the Ecobee app.

After opening the web portal or app, go to the “Reminders and Alerts” tab. Select Preferences and then Aux Heat Runtime Alert. You can either disable the alerts completely or change the alert thresholds.

Reset Thermostat

If after changing your settings and turning the alerts off you still receive them, you can reset your thermostat. This reverts your thermostat back to its factory setting. Any personal preferences are deleted, but hopefully, this fixes any bugs.

To reset your thermostat, go to the touch-screen of the thermostat and press Menu > Settings > Reset. From here, Ecobee has five factory setting options:

  • Reset All Settings
  • Reset Schedules and Preferences
  • HVAC Equipment Settings
  • Reset Registration
  • Reset Contractor Info

Select the option that works best for your needs.

Reset All Settings

This option erases all personal settings, preferences, and registration from your thermostat. Choosing to reset all settings results in your Ecobee functioning as it did when you first received it. You will need to reprogram all personal information and settings after choosing this option.

Reset Schedules and Preferences

This erases all schedules, programs, and preferences back to the default setting. However, the Ecobee thermostat will still be registered to you.

HVAC Equipment Settings

This resets the connection between the thermostat and your HVAC system, including any thresholds and sensor configurations.

Reset Registration

Resetting your registration unlinks your thermostat from your personalized web portal. Your email address and password associated with the thermostat will no longer work. You’ll have to re-register your Ecobee after choosing this option.

Reset Contractor Info

This erases any information that was input regarding the contractor who installed the thermostat.

Customer Care

If none of these reset options fixes the alerts, contact Ecobee Customer Care for further assistance. They will be able to help you troubleshoot or guide you through the warranty process.

Related Questions

What happens if my auxiliary heat runs for too long?

Other than an alert from Ecobee, the only thing auxiliary heat affects is your heating bill. The alert from Ecobee simply lets you know your more expensive heat system has been running for a while. The HVAC system is not adversely affected by the runtime of auxiliary heat.

Is it bad to run AUX heat?

Running auxiliary heat isn’t bad at all. In fact, when it runs, it allows your house to maintain a comfortable temperature when your regular heat can’t. As stated in the question above, the only thing “bad” about running auxiliary heat is the added expensive.

Is auxiliary heat the same as emergency heat?

Auxiliary heat and emergency heat are two different things. Auxiliary heat turns on automatically, taking over for the main heat pump when it can no longer sufficiently warm the house quickly enough. The emergency heat needs to be switched on manually and shouldn’t be used in temperatures above 30°F.

Should the heat pump and AUX heat run simultaneously?

You have the option with Ecobee to allow the heat pump and auxiliary heat to run at the same time. When setting up your Ecobee, you can choose to configure your heat pump in certain ways. One way is to allow the heat pump and auxiliary heat to run simultaneously. For the first 30 minutes, your heat pump runs on its own. If, after that time, the set temperature hasn’t been met, your auxiliary heat kicks on as well, assisting the heat pump to reach the set point.If you choose not to engage this option, your heat pump runs for 2 hours before switching to the auxiliary heat if the setpoint isn’t met.

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Summing It Up

If you receive a message from Ecobee stating your auxiliary heat is running too long, don’t panic! This alert simply lets you know you’re using the more expensive heating option. Your HVAC system is perfectly fine and functioning as it is programmed. You can get rid of these alerts with a few strategic changes to your Ecobee.

Change the minimum compressor outdoor temperature threshold but only if your equipment can run safely at a lower temperature.

Set a minimum runtime for the auxiliary heat and/or the compressor. Setting a specific run time allows you to use the auxiliary heat only when necessary.

Turn off alerts. If the idea of running your auxiliary heat doesn’t trouble you, turn off the alerts from Ecobee.

If all else fails, reset your thermostat. This will hopefully get rid of any bugs in the system.

Brigid Levi
Brigid Levi

Brigid Levi is a wife, mother, and freelance writer who enjoys a good DIY project and creating beautiful spaces within her home. From cleaning and organization hacks to home decor ideas, she loves helping people in their quest to turn a house into a home. Her hobbies include pretending to be Joanna Gaines while updating her home with her husband and performing in local theater productions.

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