The CH is working fine but for some reason the hot water takes a long time to kick in and I have to turn the tap on FULL for the boiler to kick in. Then when I close the tap a bit to a sensible stream, the boiler stops and the water goes cold again. This is the case with or without CH on.

Gav, November 2008

Thanks Alan. Don't suppose you know if that's something I can do myself or is it a repairman job?

Gav, November 2008

sounds like diaphragm in diverter valve is split.it will need changing

alan, November 2008