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
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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.
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Continue Troubleshoot E296, N262 and N412 codes
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.