My wifi Nest Thermostat has worked perfectly for several years until a few days ago. The settings and Wifi connection all appear to be OK. However, the heating is ignoring settings on the Thermostat and the app and is permanently on heating to 18C 24/7 regardless of the settings.
Histoy shows 'no usage' for the past 3 days. Not so!
I have reset the app. Tried having it 'off' for several hours. Heatlink green light is permanently on.
Help!
