this is usually caused by the plate heat exchanger being full of scale or debris, worth checking the temperature sensor and flow sensor. usually the best value and i hate to reccomend british gas, because their engineers are usually , trying to push replacement boilers and service contracts and are so often trouble making arrogant pigs. rant over, british gas do any boiler any fault for 192 pounds inc vat, in this senario its the best value, then get an independant installer to fit a magna clean to keep debris out from the heating system and a scale reducer on the cold water inlet, this will lighten your wallet my friend, but your boiler will be almost new again
john, February 2010
