Boiler random start

[Mbw01]

I recently had my boiler serviced (nozzle, clean, etc), but since the service the boiler is turning on randomly and repeatedly. It appears to be hot water only as the radiators do not heat up.

when randomly running, the thermostat does not recognise it as running and I can therefore not turn it off.

i can however control heating/water with the thermostat when the boiler is in the off state.

Any ideas what could have happened to cause this?

[alejandom]

Hi @Mbw01,

First I would like to thank you for posting in our community page, on the other hand I apologize for the inconvenience that you are having with your Nest Thermostat. Let me tell you some troubleshooting steps that you can try to fix the problem.

 There are a few possibilities for why your boiler might be turning on randomly for hot water only, and the thermostat doesn't seem to recognize it:

1. Faulty System Components:

• Temperature Sensor: A malfunctioning temperature sensor in the boiler could be sending false readings, tricking the boiler into thinking it needs to heat the water even when it's already hot.
• Control Board: Less likely, but the boiler's control board could be malfunctioning and sending incorrect signals to turn on the boiler.

2. Wiring Issues:

• During the service, it's possible a wire became loose or disconnected, creating an unexpected circuit that triggers the boiler to activate for hot water.

3. Incorrect Settings:

• Hot Water Priority: Some boilers have a setting that prioritizes hot water heating over central heating. It's possible this setting was accidentally changed during the service.

If for some reason you still have the same issue don't hesitate to let us know.\

Regards,

Mario.