Hi folks

I wonder if you could help me with the following problem - I have a Worcester Bosch Greenstar ri (15 I think) condensing boiler (it's not a combination) and it's decided to have the following problem:

The boiler produces hot water and central heating in the normal way but stops heating the radiators when the hot water is...erm...hot. So even though the thermostat shows the central heating needs to be on - the boiler won't heat the radiators unless it is heating hot water for the taps.

Interestingly, if we run the hot water tap for a while, the boiler kicks in and heats the water/radiators. So whether the boiler is heating the radiators is entirely dependent upon whether it kicks in to heat hot water.

Rambling, I know, and sorry for that - but any clues of the reason? The boiler itself seems to work fine.

Many thanks for your help.

Richard

Richard, January 2010

I mean I "don't" remember seeing any control on the cylinder...

Richard, January 2010

Many thanks for your response - silly question, but where will the cylinder thermostat be located? On the cylinder itself or on a pipe feeding the cylinder? (I remember seeing any control on the cylinder but I do know there is a dial of some sort near the pump next to the valves).

Richard, January 2010

Your diverter/zone valve is faulty. as a short term fix you can turn up your cylinder thermostat.

Henry, January 2010