Smart thermostat (Nest/Hive) not controlling heating

Free DIY guide — no sign-up required. Written by a qualified Gas Safe engineer.
DIY Friendly💷 £0£5020–45 min

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Most likely cause & what to check

1

Check the Nest or Hive app — confirm the schedule is active and the target temperature is above the current room temperature shown on the device.

2

Check the thermostat has power — Nest and Hive thermostats are battery powered or wired. If the display is blank, replace the batteries (AA or AAA) or check the wiring at the base.

3

Check your Wi-Fi router is working and the thermostat has an active connection. Smart thermostats rely on a constant internet connection to operate remotely.

4

Try controlling the heating directly from the thermostat itself (not the app) — press and hold the thermostat to boost heating. If the boiler fires, the problem is app/connectivity-related.

5

Check the receiver unit — Hive and some Nest systems have a receiver box at the boiler. Confirm its LED is green and it is in AUTO mode, not OFF.

6

If the boiler still will not fire despite the receiver showing a call for heat, the issue is with the boiler itself. Check for fault codes and call a Gas Safe engineer.

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