I have had this bioler over 8 years it's never give enough hot water for a bath or sink. the heating works fine the radiators are red hot. when the radiators are on you can get hot water for a time then goes coldish not enough to run a bath. I have read a couple of articles relating to this some say diafram or microswitch i'm gonna give it a go and change the diafram if this is the problem. any more help would be appreciated or you know something else

Saul, October 2008

If it has >never< given enough hot water for a bath then it may have not been properly commissioned. When there is hot water demand the gas valve is meant to open full crack to give maximum heat output. If this is not happening the hot water throughput will be poor. This is realy is a job for a corgi man who knows his way round the boiler. Other problems with microswitches, diaphragms, venturi etc develop with age and are never present on a brand new boiler.

c, October 2008