Now the weather is warmer I have turned the heating off but still got the water coming on for an hour in evening. When water heater turns on, the radiators get really hot even though the thermostat is turned right down. Didn't have this problem last summer. The control panel is a Potterton EP2000

Niki, April 2011

Thank you Brian, is that something I could check or would you recommend getting a plumber in?

Niki, April 2011

like my last answer this is likeley to be a motorised valve stuck open slightly

brian, April 2011