Heating too hot - unable to turn it down.

[CBW]

Sounds more likely to be a failed/failing motorised valve, and or immersion left on for hot water. Could the MIL be turning the heating up? You can get tamper proof covers.

 

[ericmark]

a new analogue room stat replaced the old analogue room stat

The analogue thermostat is far better than digital if the boiler can use them. But what type of analogue thermostat? Although I have an analogue thermostat fitted, it is connected up as a digital one as my boiler does not modulate.

 

[Mottie]

The analogue thermostat is far better than digital if the boiler can use them. But what type of analogue thermostat? Although I have an analogue thermostat fitted, View attachment 262190 it is connected up as a digital one as my boiler does not modulate.

This type although not sure it was a Honeywell.

 

[Mottie]

Mrs Mottie turned it down and remarked that it was 'clicking off/on' around the 15-17° mark. We weren't there long enough for it to cool down. Mrs Mottie went round today to check on her (poss onset of dementia) and again, it was like a furnace in there. There was another thermostat above the room stat and Mrs Mottie said it was showing 26° But still clicking on/off around the 16° mark.

Installer came back today. It was a faulty room stat so he replaced it. All good now.