My Baxi Solo boiler has just started to turn on even without demand, i just upped the thermostat as the house was a little cool. The boiler then kept firing up even though the room stat said no demand, i then turned the heating and the Hw off completely, it still fired up. I have had to turn the boiler off at the mains to stop the boiler

Richard Irons, August 2012

the fault is with your motorised valve not the boiler, the end switch is stuck, try moving the valve to the manual position that should free it

Martin, August 2012