At SmartHomePerfected we pride ourselves on providing trustworthy, unbiased information. If you buy through links on our site, we may earn a small affiliate commission at no extra cost to you. Learn more

Troubleshoot the Nest thermostat blinking lights with our expert guide to ensure optimal performance and energy efficiency. Nest thermostats (and Nest “Heat Links” in Europe) can put out nearly half a dozen different blinking lights and patterns. 

Most of the time, these are simple indicators notifying a restart or a software update. 

However, they can also be trying to indicate a serious issue, so keep reading as I explain each color and show you how to fix them. 

At SmartHomePerfected we always advise readers not to undertake any work they are not competent in performing and if in any doubt, it is best to seek the assistance of a professional.

Compatible Models

Don’t worry about compatibility as this guide encompasses all available Nest thermostat models, in North America and Europe. 

This includes …

  • 1st, 2nd, and 3rd generation Nest Learning Thermostats
  • Nest Thermostat E
  • Nest Thermostat (2020 model)
  • (If in Europe) their corresponding Heat Link devices.

Where appropriate, I’ve provided links to specific articles that will help you get your Nest thermostat or Heat Link back up and running. 

So let’s get into it!

Nest Thermostat Blinking Lights: Red

The Red blinking light might be the most alarming. However, after you know why your device starts putting out a flashing red light, you won’t have to worry anymore. 

Along with a flashing red light, the screen on your Nest thermostat can also go completely blank. You might see a house icon blinking green in the middle of the screen.

Whatever the case, when the Red light is blinking, it is often trying to tell you that the battery on your Nest thermostat is running low. 

So to diagnose this issue further, I recommend checking out my dedicated guide on resolving battery issues on a Nest thermostat.

Nest Thermostat Flashing Green 

Nest Thermostats receive software updates regularly from Google. If you see a blinking green light on your Nest Thermostat, it means your thermostat is updating the software, installing an update, restarting, or starting up. 

This should only last for a minute or two and then the flashing light will stop. So the first thing you should do is to wait.

However, if the flashing green light doesn’t go away, or if you encounter a steady green light that doesn’t blink, it means your Nest Thermostat has frozen. 

This can happen while it’s carrying out a software update and this troubleshooting guide will help you fix the issue.

Nest Thermostat Blinking Lights: Orange

The blinking orange light might be the most confusing because it can show up even when the device is operating smoothly. 

Your heating and cooling systems might work as usual but the Nest thermostat or Heat Link might be putting out a flashing orange light. 

There can be several reasons why an orange light shows up depending on the North American and European versions. As such, I recommend reading through this article for a comprehensive troubleshooting guide.

Nest Thermostat Flashing Yellow

If you’re seeing a flashing yellow light and your Nest Thermostat is failing to heat your house and warm water, it might be that the Heat Link has disconnected from your Nest thermostat.

As such, the yellow blinking light issue is specific to the European version of Nest Thermostats as the US models do not come with a Heat Link. 

So to make the yellow blinking light go away, you need to re-establish the connection with your Heat Link. 

Depending on the model, the steps involved to fix the issue can become quite complicated. So check out my definitive guide on fixing the yellow blinking light on European Nest thermostats and Heat Links.

Nest Thermostat Blinking Lights: White

If you come across the blinking white light in your Nest thermostat, chances are you are also finding it hard to start up your thermostat or control it via the app.

There can be several occasions why this might happen. These include:

  • The Nest thermostat is trying to reconnect with the Wi-Fi router
  • The device is going through a software update
  • The thermostat is restarting

So if the white light won’t go away on its own, you can attempt to troubleshoot the issue. 

  1. Start by checking the thermostat wiring. Make sure the cooling and heating wires are placed correctly into the connectors within the Nest Thermostat.
  2. Make sure the thermostat is not loose and fixed properly onto the baseplate.
  3. Wait until the thermostat restarts for a couple of minutes to see if the light goes away.
  4. If it doesn’t try manually restarting the device
  5. To restart, press and hold the Nest Thermostat Ring until the displays go blank. (About 10 seconds.)
  6. Wait until the device fully restarts and check if the thermostat works as usual and if the error light goes away
  7. If it still doesn’t clear out, check the app or thermostat for any alerts or notifications. Then, check the heating and cooling operation of the thermostat manually or via the app
  8. If everything seems fine but the light won’t go away, try restarting again or getting help from a professional

Nest Thermostat Flashing Blue

The blue blinking light is a common indicator on Nest Learning thermostats and certain Heat Link devices. 

In the case of the Nest Learning Thermostat, the device typically indicates the blue blinking light during startup.

For these models, the light should go away after a minute or two. If it doesn’t, you might need to manually fix it.

If the flashing blue light is on the Heat Link, there might be connection errors between the thermostat and the Heat Link, so check out this article for a detailed troubleshooting guide.

No Light On My Nest Thermostat

Is the screen blank on your Nest thermostat? If that’s the case, don’t panic because as long as it hasn’t broken down or shown signs of obvious damage, it can be fixed with just a few steps

When the display goes blank or dies out without any indicator lights, it usually means the battery has drained out completely. So once you recharge the device, and fix any wiring issues, the screen will light up again.

Combination of Nest Thermostat Blinking Lights: Green and Orange

Along with individual blinking lights, you might also encounter a combination of colors, the most common of which are the blinking yellow, and green lights. 

So if you are getting the Yellow and Green blinking light combination, chances are your fan might start to act crazy or your thermostat and Heat Link might be stuck in a reset mode or pairing process. 

Different fixes apply for different models, so to learn how to troubleshoot these issues, make sure to check out my dedicated article on “Nest thermostat combination of blinking lights” 

Wrapping Up

If the blinking indicator lights on your Nest thermostat and Heat Link don’t go away on their own, it usually means there’s an underlying power issue, software glitch, or network failure. 

Learning what each color means and how to fix them efficiently can go a long way, so make sure to read this article, check out the detailed guides and drop a comment if you run into any major issues.

Referenced Sources

Show CommentsClose Comments

Leave a comment