Furnace Heads-Up can notify you 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 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, Google Home or Nest app, and Nest Home Report.
Note: If you migrated your Nest account to a Google Account, you’ll get the notification in the Home app. If you haven’t migrated your account, you’ll get the notification in the Nest app.
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 option to dismiss the alert.
The Heads-Up will only appear on your thermostat and in the app once, each time it detects an issue. You’ll get a Heads-Up in your Nest Home Report each month there’s a potential problem.
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 is OK, contact a local pro. Remember, you can also set up Filter Reminders that’ll let you know when it’s time to change your filter. Check Air filters and filter reminders for detailed instructions.
2. Test to check if the air filter fixed the issue
If you get a Furnace Heads-Up alert, there’ll be a new option for Furnace Heads-Up testing in the thermostat's System Test menu:
Nest Learning Thermostat (3rd gen and earlier) and Nest Thermostat E
- Press the thermostat ring to bring up the Quick View menu.
- Choose Settings
Equipment.
- You’ll find the wires you’ve connected to your thermostat. Choose Continue.
- Your system components will show (Heat, Fan, and Cooling, if you have them). Select Test.
- Select Furnace Heads-Up, then follow the onscreen instructions.
- Your system will run a heating test for 15 minutes, and tell you the results at the end.
Test your system with a Nest thermostat
Note: Your Nest thermostat must be connected to Wi-Fi and the internet for the test to run. If it’s not, there’ll be an alert to let you know.
If your system’s air filter is okay, or your system didn’t pass the System Test after changing the filter, there might 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 might require service by an HVAC professional. Your thermostat will display a note to contact a pro to identify and resolve the issue. If you’ve had a Nest Pro install your thermostat, it’ll provide their name, contact details, or a QR code to connect with them. For more help,
contact a local pro.
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 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 isn’t a foolproof way to detect a problem with your forced air heating system and shouldn’t be relied upon as a way to monitor whether your heating system is working properly. These notifications aren’t intended to be a substitute for regular system service by an HVAC professional.
Equipment.