If you’ve successfully installed your Nest thermostat, but a blinking red light appears after you’ve been using it regularly for some time, there may be a problem with the thermostat wiring or another power issue. For instance, the blinking red light may show up then go away on itsown repeatedly. If your thermostat shows you a blinking red light, the battery is charging and it'll eventually turn on. It can take up to an hour if the battery is extremely low. The Nest Thermostat can be wired into any Combi boiler by a qualified heating installer or electrician. If there'sa help message on your thermostat or in the app, follow the troubleshooting steps in Troubleshooting Nest thermostat error codes. To help you identify whether your heating system is a high voltage, millivolt, or proprietary, we’ll try to describe them:

Nest thermostat - Google Nest Help Install your Nest thermostat - Google Nest Help

If your Nest Thermostat won’t turn on, the batteries could have drained or there could be a power issue. If your Google Nest thermostat won’t turn on and there'sa blinking red or green light, or no light at all, there could be a power issue or your thermostat may have frozen during a software update. Follow the troubleshooting steps below that match the issue you're seeing. Before you begin If you’d like to install your Nest thermostat yourself, everything you need is included in the box: To get a custom wiring diagram for installation, simply follow Nest app’s thermostat installation instructions. However, if the old thermostat works perfectly with your system, your Nest thermostat might be seriously damaged.If this fix doesn’t help with the blank screen problem, continue to the next step. Fix the Thermostat Display onto the Base Properly

Nest Thermostat E

A blinking green light near the top of your Nest thermostat’s display means that it’s updating the software, starting up, or restarting. Typically, this will only last a minute or two. Once your thermostat has finished starting up, it'll turn on so you can use it. As Boilers and radiators are installed by third parties, they do have to install in compliance with regulations and manufacturer standards to get the full benefit of the warranty.If the Voc, Vin or lin values are not within the specific ranges listed here, there may be a wiring or system issue: Turn off power to your system at the breaker box or system switch. This will help protect your system and your thermostat from possible damage. The Nest thermostat is incompatible with high voltage, millivolt, and proprietary heating systems. If you use the Nest thermostat with any of these heating systems, it may not get sufficient power to charge its battery.