my ravenheat boiler is not providing hot water when it is switched to hot water only. the hot water is also not constant and when taps are opened fully the water runs cold. there are also black bits coming out of the hw tap. the heating pipes are also hot when all rads switched off. any ideas anybody?

rozzer, July 2008

I think heat exchanger also - they cost 200.00 - scrap the boiler !

jon hinch, January 2009

This will be due to a blocked plate heat exchanger.

Chris, August 2008