for the last month my hot water is not getting hot enough you don't need to put any cold water in. we have a service contract with British gas the engineer came out asked for the manual for the boiler to see if he could find the problem after one hour he came to the conclusion that the boiler and radiators need flushing out at the cost off £695 PLUS VAT something i have noticed hot water tends to be hotter when central heating has been .can anybody offer any advice or the possible fault thank you