wooster bosch 42cdi greenstar

[simonn]

I have a 42cdi fitted when you turn the tap on for hot water the raditors warm up at the same time even if the the central heating is turned off when you turn the tap off the rads go cold again almost if a valve is stuck half way.any clues

simon

 

[kevplumb]

diverter is duff

 

[gaspro1981]

sounds like the classic symptoms of a failed diverter valve it could just be partially blocked with carp/sludge which you could try and clean out but it may be worth while replacing the complete unit/assembly imho

 

[LeedsPlumber]

As stated previously it will be diverter motor, if less than 2 years old should be covered under warranty