Troubleshoot Furnace Heads-Up

Furnace Heads-Up can let you know when your Google Nest thermostat has detected a problem with your forced air heating system. To troubleshoot, you should run a quick system test to confirm there’s an issue.

If your Nest thermostat detects that your furnace
hasn’t been able to heat for longer than 15 minutes at
a time, you’ll get a Furnace Heads-Up message on your Nest
thermostat, in the Nest app, and in your Nest Home Report.

The message on the thermostat will say, “Nest noticed
that your furnace shuts down within 15 minutes of
heating” and you’ll be given a link to this
troubleshooting article and the option to dismiss the

Nest thermostat furnace shutdown display image.

Note: You’ll only see the Heads-Up on your thermostat and in the app once each time it detects an issue. You’ll see a Heads-Up in your Nest Home Report each month there’s a potential problem.

How to troubleshoot Furnace Heads-Up

If you see a Furnace Heads-Up message, you should troubleshoot your system as soon as you have a chance. Here’s what to do:

1. Check your system’s air filter

A clogged filter is one of the most likely reasons a furnace might shut itself off. If your filter looks OK, skip to step 3. Remember, you can also set up Filter Reminders that will let you know when it’s time to change your filter.

      Learn more about changing your air filter >

      Learn more about Filter Reminders >

2. Test to see if the air filter fixed the issue

If you get a Furnace Heads-Up alert, you’ll see a new option for Furnace Heads-Up testing in the thermostat's System Test menu.

  1. Press the thermostat ring to bring up the Quick View menu.
  2. Choose Settings > Equipment
  3. You’ll see the wires you have connected to your thermostat. Choose Continue.
  4. You’ll now see your system components (HeatFanCooling if you have them). Select Test.
  5. Select Furnace Heads-Up and follow the onscreen instructions.
  6. Your system will run a heating test for 15 minutes, and tell you the results at the end.

        Learn how to run a System Test >

Note: Your Nest thermostat must be connected to Wi-Fi and the internet for the test to run. If it’s not, you’ll see an alert letting you know.

3. If changing the filter didn’t fix the issue, contact a local pro

If your system’s air filter looks OK, or if your system
didn’t pass the System Test in step 2 after changing the
filter, there may be other issues. Your furnace’s
behavior could be caused by a clogged evaporator coil,
broken fan motor, blocked air ducts or heating vents,
poor gas pressure, or another issue that may require
service by an HVAC professional. We recommend that
you contact a local pro to service your system.

If a professional installed your Nest thermostat, they
should have entered their contact information on the
thermostat. Here’s how to find it:

Nest thermostat generation 3 pro-contact information.
  1. Press the thermostat ring to bring up the Quick View menu.
  2. Select Settings.
  3. Choose Nest Pro. You should see your installer’s contact information.

If there isn’t any pro contact info on your thermostat or you don’t have a regular HVAC pro that you use, contact a local pro to service your system.

Limitations of Furnace Heads-Up

You can get Furnace Heads-Up notifications on the Nest thermostat whether or not your thermostat is connected to Wi-Fi and the internet. Furnace Heads-Up notifications in the Nest app and Home Report require your home to have a working internet service and Wi-Fi connection to your Nest thermostat. The notifications are relayed over the internet and can only work if the internet and Wi-Fi in your home are working. So if your Wi-Fi network goes down, it could adversely affect the availability and accuracy of Furnace Heads-Up.

Furnace Heads-Up is not a foolproof way to detect a problem with your forced air heating system and should not be relied upon as a way to monitor whether your heating system is working properly. These notifications are not intended to be a substitute for regular system service by an HVAC professional.

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