Hi

Thanks for youre responses.

I don't know much about boilers and plumbing but here's a description
of what's (I think) is happening.

When I turn on any hot water tap, sometimes there's no hot water. I
turn the tap off and then back on an there's an audible click from the
boiler and the boiler fires up - producing hot water from the tap €“
this can take several attempts. A plumber has advised that in the
boiler there a valve that switches between hot water and heating. He
stated that a build up of limescale may prevent this valve from
working efficiently. Adding descaler to the system, he said, would
cure it.

I don't know the details of the boiler - I will get them and post them
tomorrow if this helps

Cheers
Nick



raden wrote in message ...
In message , Nick
writes
My central heating is controlled by a combi boiler. Occasionally the
hot water doesn't come on when the hot water tap is turned on. Having
spoken to a plumber he says that the problem a valve in the boiler
getting stuck because of a build up of limescale. The boiler also
€˜buzzes' a bit when the heating is on. He has advised me to descale
the system using descaler fluid.

Can anyone advise me how to descale the system €“ the plumber advised
on draining a radiator and topping it up with the fluid €“ how do I do
this ?

Does it come on for a short period ?
This would indicate limescale

I think you would be wise to post more details to the group in order
that a proper diagnosis might be made

what boiler for example