Water only getting hot when the central heating is on

[AndyColeman]

Hi,

I have a Worcester 28CDI combi boiler. When the central heating is on the water from the taps in the kitchen and bathroom comes out hot no problem. But when the heating is not on it is very difficult to get the water anything more than luke warm. When the hot water is running the boiler is on and seems to be doing what it should be doing. The boiler is about ten years old and this problem has only appeared in the past few months.

Not sure if this is a clue but I noticed tonight after trying to get the water hot enough for the kid's bath that the radiators were a bit warm even though the heating had not been on.

Thanks for any help

Andy

 

[45yearsagasman]

You have a fault on your diverter valve. As its passing to rads when on hot water, I would replace the whole diverter, And its not a job for the feint hearted. While you're at it get the plate heat exchanger cleaned.(It has to come out to gain access to the diverter).