I have 2 nest thermostats, one each for upstairs and downstairs. Last night my burner was on heating upstairs. Turned down nest thermometer. 30 mins later I notice burner is going again and heating upstairs, heating is turned off upstairs and downstairs, what we heating isn’t turned on. All thermostats and apps say heating is off but the burner still keeps going and heating upstairs only.
I’ve tried everything, reset the thermostat upstairs, even through the app I’ve disabled the upstairs thermostat from heating but it’s made no difference, it keeps turning on the burner even when target temp is reached it still keeps turning on the burner but only affects upstairs.
I’ve had to go outside and manually turn the burner off.