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Nest thermostat: H1, H71 or H151: can’t reach the Heat Link

H1
Our drawing: “H1”, on a round thermostat.

The thermostat can’t connect to your Heat Link to control your heating. The Heat Link’s status light is yellow while it is disconnected from the thermostat.

Applies to: Nest Learning Thermostat and Nest Thermostat E with a Heat Link. What you see: a code.

Codes this page covers: H1 H71 H151.

What Google says to do

  1. Restart the Heat Link: hold its button until the light turns off (about 20 seconds), release and wait. A green status light means it has reconnected.
  2. If the thermostat is on a stand, move it closer to the Heat Link; keep large metal or dense objects such as mirrors and fridges out of the way, then run Settings, Equipment, Continue, Heat Link Test. A few centimetres can make a difference.
  3. Turn off other 2.4 GHz devices (cordless phones, baby monitors, microwave ovens, wireless cameras) one at a time to find interference.
  4. Google says that if this does not fix it, contact a Nest Pro.

Source

Google’s own help page, read on the date shown.

  • Google Nest Help: Troubleshoot Nest thermostat help codes — Nest Learning Thermostat (1st to 4th gen), Nest Thermostat E and Nest Thermostat; H codes only where a Heat Link is installed. support.google.com Checked 2026-09-29.

Other Google Nest thermostat states