Set Square, thanks for your time and advice.


Set Square wrote:

Has it ever worked? Has this problem arisen since someone did some
alterations or repairs to the system?

It has worked much better in the past than it does now, although
problems seem to come and go. The upstairs rads have always needed
frequent bleeding, and the system has always been noisy, in terms of
running water. There hasn't been any work done, other than a boiler
service a year or so ago.



My first thoughts are that the pump is pumping in the wrong direction
- and
needs turning round. But we really need more details of the system
type.

Are both heating and hot water pumped, or is HW primary circulation
by
gravity (convection)? Are there any motorised valves? If so how many,
and
does each one have two or three water connections? [Photos of the
pipework
in the airing cupboard - if that's where the valves/pump are - would
be
useful].

My system consists of a Baxi Bermuda located behind my gas fire
downstairs. The pump is under the downstairs floorboards. I think (but
I'm not sure, sorry) that the HW is circulated by gravity. I really
couldn't answer about the motorised valve. I haven't noticed any around
the pump or in the airing cupboard, but this doesn't mean there aren't
any (it's generally inconvenient getting to the pump)



Which header tank is overflowing - the large cold tank which feeds
the
domestic hot water system, or the small tank for the heating system?
If it's
the small one, is the ball valve working ok? What is the water level
when
the system is cold? [There should be only 2 or 3 inches of water in
the
tank - with the level a *long* way below the overflow to allow for
expansion].

It's the small one that is slightly warm that sometimes overflows (but
hasn't done for some time.) The ball valve is fine, and the water level
is normally well below the outlet.)

I used to be able to bleed the radiators with the pump running in the
past, but like I said, if I do that at the moment, the rads appear to
drain. Where could the water be going? I haven't spotted a leak
anywhere (and I did look under the floorboards too


That'll do for starters!
--

I appreciate the help, if there's any more info I can give, I'll gladly
do so.
Many Thanks,
Bob.