My central heating seems fine, but when I turn on the taps, I get some hot water but it tends to go luke warm quickly. Also, when the heating is turned off, turning the shower on does not seem to start the boiler running like it should. It's been like this for a few months now. Any ideas?

Mark, January 2009

Your boiler doesn't know there is a demand for hot water if it only gives warm water in CH mode (lower flame) Get an engineer to look at it. It'll be an easy fault to diagnose and fix.

Iain, January 2009