I ahve a Potterton combi boiler and 3weeks ago it started firing for 3 mins then turning off for 2 mins then on for 3 mins and off for 2 and so on. its always playing catch up! The radiators are hot but heat can't be felt unless you're next to the radiators. The room is warm but never comfortably so. Is it the boiler? If so what could be wrong?

King tupps, January 2010

make sure you have no dripping taps, this will stop your boiler from switching fully to the heating mode.

Henry, January 2010

maybe the pump or sensor (or diverter valve if its a puma or combi 80)

Ian, January 2010