Learn about the lights on Heat Link and what they mean

The lights let you know if Heat Link is connected to your Google Nest thermostat. If it’s disconnected and you need to turn on manual heating, the lights will tell you when your system is running.

Each model of Heat Link has different lights that mean different things. Select your Nest thermostat and Heat Link model below. If you’re not sure, see our article about how to tell which Nest thermostat you have.

Heat Link for Nest Thermostat E 

Light

What it means

No light

Usually, no light means everything is working
as expected. Heat Link’s light will stay off
during times when it’s connected to your
Nest thermostat and everything is working
normally.

Of course, if Heat Link has lost all power, the
status light will also be off. If this happens,
you should see an error in the Nest app or on
your thermostat.

nest thermostat yellow status light

Status light

Blinking yellow: Something needs your
attention. Check your thermostat screen for
an error code or other message.

Pulsing or breathing blue: During setup, Heat
Link will pulse or breathe blue to let you
know it’s currently connecting to your
thermostat and the Nest app. If you’ve
restarted Heat Link, it will pulse blue while
it’s re-connecting.

Quickly blinking blue: Heat Link is updating
its software.

nest thermostat green status light

Heating light

Pulsing green: Heating is currently on,
controlled by your thermostat.

Solid green: Manual heating is currently on,
controlled by pressing Heat Link’s button.
Your system will continue to heat your home
until you press Heat Link’s button again to
​turn off manual heating

Heat Link for 3rd gen Nest Learning Thermostat 

The lights on the 3rd generation Heat Link let you know that everything is working the way it should be or if the Heat Link has lost connection to the Nest Thermostat.

heat link light image

The Heat Link’s status light will typically be solid green, but it may also be a solid blue or yellow, or even blinking, depending on the situation. The heating and hot water lights will normally be off unless you manually turn on heating and hot water.

           How do I turn on the heat if my Nest Thermostat isn't working? >

During setup

During setup, the Heat Link’s status light will let you know what’s going on. The heating light (in the shape of three wavy lines) and the hot water light (shaped like a water drop) will be off.

 

Status light

 

 

Heating light

 

 

Hot water light

 

 

What's happening

 

blue slow light
Pulsing blue, slowly

OFF

OFF

The Heat Link is
ready to pair with
the Nest Thermostat.

            How do I pair the Nest Thermostat and Heat Link? >

During normal operation

When things are working like they should, the Heat Link’s status light will be a steady green. The Heat Link’s heating light and hot water light will come on when heating and hot water are turned on manually.

 

Status light

 

 

Heating light

 

 

Hot water light

 

 

What's happening

 

status light green
Steady green

OFF

OFF

The Heat Link has
been set up and is
on. This means that
it’s online, powered,
and working as it
should be.

status light green
Steady green

gen 3 heat light green
Steady green

nest thermostat hot water green icon
Steady green

The Heat Link is
connected to the
Nest Thermostat,
online, powered, and
working as it should
be.

Heating and hot
water are manually
turned on after the
Heat Link’s button
was pressed.

 

When the Heat Link is disconnected from the Nest Thermostat

Most of the time, the Heat Link’s status light will be green. But in rare cases, the Heat Link can become disconnected from the Nest Thermostat. When this happens, the Heat Link’s status light will be yellow. If the Heat Link becomes disconnected, you can still turn your heating and hot water on manually.

 

Status light

 

 

Heating light

 

 

Hot water light

 

 

What's happening

 

nest thermostat yellow status light
Steady yellow

OFF

OFF

The Nest
Thermostat has
become disconnected from
the Heat Link and can’t
control heating or hot water.

How to troubleshoot
when your 3rd
generation Nest Thermostat can't
connect to Heat Link
>

nest thermostat yellow status light
Steady yellow

gen 3 heat light green
Steady green

nest thermostat hot water green icon
Steady green

The Nest
Thermostat has
become disconnected from
the Heat Link and
can’t control heating
or hot water.

How to troubleshoot
when your 3rd generation Nest
Thermostat can't
connect to Heat Link
>

Heating and hot
water are manually
turned on after the
Heat Link’s button
was pressed.

Heat Link for 2nd gen Nest Learning Thermostat 

This light on Heat Link lets you make sure that everything
is working the way it should, and tells you if something is
wrong.

During normal operation, the Heat Link light will typically
be solid green, but may also blink green or yellow
depending on the heating status.

2nd gen Heat Link

 

During normal operation, the Heat Link light will typically be solid green, but may also blink green or yellow depending on the heating status.

Heat Link light Status What's happening

status light green

Steady green

Connected

Nest Thermostat and Heat
Link are connected.

blink green

Blinking green

Heating

The Nest Thermostat has
sensed that your room
needs more heat, and it’s
firing up your heating
system.

 

blink yellow

Blinking yellow

Heating (manual mode)

Heat Link is in manual heat
mode: it’s directly turning on
the heat. Press the Nest
button to put Heat Link into
manual mode if your
thermostat is having trouble controlling the heat. Press it
again to put the Nest
Thermostat back in control.

Learn more about manual heat mode

During pairing, setup or a reset to factory defaults you may see the following lights.

          Learn more about the pairing process

Heat Link light Status What's happening

blink green yellow

Blinking yellow and green

Searching for thermostat

When the Nest Thermostat
and Heat Link are set up,
they need to be paired so they can speak with each other.

If the light on Heat Link
blinks yellow then green
every other second, it’s
ready to be paired to a new thermostat. This should only
occur during installation or
when Heat Link has been
reset to factory defaults and
is looking to re-pair with the thermostat.

blink green yellow fast

Quickly blinking yellow and green

Reset to default

The light on Heat Link
quickly blinks yellow and
green if it’s being reset to
factory defaults. To reset
Heat Link to factory
defaults, hold the Nest
button down for 20 seconds
until you see a fast blinking
yellow and green light.

Learn more about resetting to defaults

Most of the time, Nest Thermostat and Heat Link will have a green light. If you have a wireless installation, in rare cases Heat Link can become disconnected.

Heat Link light Status What's happening

 

nest thermostat yellow status light

Steady yellow

Not heating (disconnected)

Nest Thermostat has
become disconnected from
Heat Link and cannot
control heating.

Help troubleshooting

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