Hardware Smart Home

What do the lights on the Nest Heat Link mean?

gray Nest thermostat displaying at 63
Never be confused by your Heat Link's flashing again

If you use a Google Nest Thermostat then, chances are, you have a Nest Heat Link – a device that connects to your existing boiler and then wirelessly communicates with your thermostat. Depending on which version of the Heat Link you have, there are lights, or a single light, which can show different statuses. But what do they all mean?

Round grey Heat Link for the Nest Thermostat E

There are two lights on the Heat Link for Nest Thermostat E, both situated on the plastic circle in the centre of the device. At the top is a status light and, at the bottom, a heating light.

Status light: Not lit

Either everything is totally fine or there is absolutely no power. Don’t you just hate it when there’s no way to differentiate something like this?

Status light: Flashing yellow

Something’s wrong – check your thermostat for details as to what it is.

Status light: Pulsing blue

During setup this indicates that the Heat Link is connected to the thermostat.

Status light: Quickly Flashing blue

The firmware is updating.

Heating light: Pulsing green

The heating is on, controlled by your thermostat.

Heating light: Solid green

The heating is on but being controlled manually by the button on the Heat Link.

Heat Link for the Nest Thermostat 3rd Gen

There are three lights on this version, arranged in a vertical line at the top centre of the Nest Heat Link – status, heating and hot water.

Status light: Pulsing blue

The Heat Link is ready to pair with the thermostat.

Status light: Solid green

The Heat Link is on and working as expected.

Status light: Solid yellow

The Heat Link is disconnected from the thermostat.

Heating or Hot Water light: Solid green

If either of these light up green then that means it’s being controlled manually from the Heat Link button.

Heat Link for the Nest Thermostat 2nd Gen

There’s just a single light on the 2nd Generation Heat Link, located at the top.

Solid green

The Heat Link and thermostat are linked successfully.

Flashing green

The Nest Thermostat has started up the heating.

Flashing yellow

The Heat Link is working manually, via the button on the device.

Flashing yellow and green

The Heat Link is attempting to synchronise with a thermostat.

Flashing yellow and green quickly

The Heat Link is in the process of being reset to factory defaults (you do this by holding down the button on the Heat Link for 20 seconds).

Solid yellow

The Heat Link and thermostat have become disconnected.

If you have other Nest devices confusing you with their flashing lights, then you’re in luck – we have what you’re looking for. For example, find out what the lights on your Nest Hello video doorbell mean in this guide.

About the author

David Artiss

Works for Automattic Inc., the company behind WordPress.com and Tumblr. Tech geek, international speaker and occasional PC Pro podcaster. Lover of Lego and video games.

Add Comment

Click here to post a comment

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.