I have the same problem - I have boiler cover and the enginier has been to see it 4 times nows - each time insisting that some part has to be changed - so far we've had new thermisters, new valve and god knows what else to the tune of about £500 in parts - still the problem pursists - the engineer now believes its to do with not enough water pressure going to the boiler although both the outside and inside pressure readings were normal - basically we've hit a brick wall - but we are getting the stop tap changed to see if that helps - if so i will let you know. But do yourself a favour, ring the water board and ask them to check your pressure readings, it is free and might save you alot of bother.
Donna, July 2008
