We have a standard British Gas celsia F1 boiler upstairs and British Gas UP2 controller with a thermostat downstairs.

The hot water heats as programmed whilst the heating works all the time irrespective of the thermostat or time/controller. The thermostat still 'clicks' at the correct temps when turning the dial but the radiators are constantly hot and probably costing me a fortune in gas :cry:

I'm not sure how reliable the controller is .... this would probably be my 1st component to replace.

any ideas or suggestions on next steps?

cheers, andy