Troubleshoot E10, E30, E66, E80, E116, E160, E196, E296, M13, N262 , and N412 help codes

What causes these errors

Google Nest thermostats are designed to work in most cases without a common wire. Instead of using a common wire to keep your thermostat charged, your Nest thermostat can use the Y1 (air conditioner) wire to power itself.

If your air conditioner stops sending power to your thermostat, your thermostat can notify you with one of these errors. There are a number of reasons your air conditioner might stop sending power to your thermostat. We list some possible reasons, but it’s important to contact a professional to diagnose your system and determine what the root cause of the error is.

• One possible reason is that your system needs maintenance. If your system breaks down, it'll likely stop sending power to your thermostat. An HVAC professional can help determine if your system needs repair.
• Another possible reason is that you live in an area that experiences very cold temperatures in winter. Your air conditioner might come equipped with a safety device that'll stop it from turning on in extremely cold weather to prevent damage. These safety devices, sometimes called low-pressure switches (LPS) or safety cutout switches, can sometimes prevent your air conditioner from providing your Nest thermostat with power in extremely low temperature conditions.

If you get one of these errors (E10, E30, E66, E80, E116, E160, E196, E296, or M13), you can use the quick fix below to help get the heat back on. Then, when it's convenient, call an HVAC professional such as a local pro to check your system and install a common wire or the Nest Power Connector.

Troubleshoot E10, E30, E66, E80, E116, E160, E196, and M13 codes

Turn off the power to your heating and cooling system at the main breaker or fuse box for your home. Important: You should always turn off the power before you connect or disconnect any wires from your thermostat, and test to make sure the power is off. This helps protect you and your equipment during installation or troubleshooting. For detailed instructions go to How to turn power off to your system.
Grip the ring of your thermostat and gently pull it off the base.
Take a picture of the thermostat’s wires. You might need to refer to it later. Remove any Y wires (Y, Y1, or Y2) from the thermostat’s base.  If you have both Rc and Rh wires, remove the Rc and Rh wires as well. Important: Wrap the exposed end of each wire you removed with electrical tape so it won’t touch any other wires. Touching exposed wires can cause a short circuit and damage your thermostat or system. Make sure the wires behind are pressed down and won’t get in the way when you reattach the display. Press the display onto the base until it clicks into place.
Turn the power to your system back on, then check if your Nest thermostat turns on without showing an alert. If your thermostat turns on without any code, you should be able to turn on the heat. If your thermostat doesn't turn on, charge or replace the batteries: If your thermostat has a USB port on the back of the display: Remove the display and connect a USB charger to the port on the back of the display. Charge it for 5-10 minutes, or until the display turns on.  If your thermostat has replaceable batteries: Remove the display and replace both batteries with new AAA batteries if necessary. Put the display back on the base. Press until it clicks into place. Check that you can turn on the heat. Important: You won’t be able to use your AC until you reconnect your Y1 wire. You should install a common wire and reconnect your Y1 wire to continue using your Nest thermostat. You might see the message, “The wiring to your equipment has changed.” Select Continue Continue Continue Done.
To prevent this from happening again, install a common wire or power accessory like the Nest Power Connector. You can purchase a Nest Power Connector and install it yourself, or contact an HVAC professional or local pro to install a common wire or power connector. If your thermostat was professionally installed, you can find your installer’s contact information on your thermostat. You might already have an unused thermostat wire that can be used as a C wire. Contact an HVAC professional or follow Fix or connect a C wire. Note: Pros are a network of independent companies or contractors and aren't employed by Google Nest.

Troubleshoot E296, N262 and N412 codes

If you receive an E296, N262 or N412 error code on the thermostat, check the battery level and replace the batteries, if necessary.

To prevent this from happening again, install a common wire or power accessory like the Nest Power Connector.

• You can purchase a Nest Power Connector and install it yourself, or contact an HVAC professional or local pro to install a common wire or power connector. If your thermostat was professionally installed, you can find your installer’s contact information on your thermostat.
• You might already have an unused thermostat wire that can be used as a C wire. Contact an HVAC professional or follow Fix or connect a C wire.

Note: Pros are a network of independent companies or contractors and aren't employed by Google Nest.