On Mon, 7 Nov 2005 15:29:26 -0000, "Set Square"
wrote:


I can only guess at the reasoning behind your (almost certainly flawed)
diagnosis. It requires no more effort from the pump to circulate water
upstairs than it does downstairs. The pump doesn't have to provide pressure
to lift the water by 3 metres because it is balanced by the return flow
coming back down - it only needs to overcome friction losses in the pipes,
provided there are no air-locks.

Nevertheless, you'd better find your pump, PDQ! Pumps don't live for ever,
and you may need to replace it one day. Are you sure it's not in the airing
cupboard?

If it's a vented system, make sure that there's some water in the small F&E
tank (not the large cold water header tank) in the attic - and that it
hasn't run dry due to a sticking ball valve. Then bleed the upstairs rads
again.

If necessary, turn off *all* rads - and then turn each upstairs rad on one
at a time to give it a bit of urge. If you can get them hot by doing that,
but they then go cold again when you turn the downstairs rads on, your
system is in need of balancing - plus you may need to increase the pump
speed if it has a speed selector (pretty difficult if you don't know where
the bl**dy thing is!)


Many thanks for the reply, I'll do as you suggest and report back ,
later..

thanks again

... Tony