can anyone offer advice please ...having serious problems with circulation here!
when the ch works it works very well but on most occasions the water isn't circulating properly and the system ends up heating up (badly/ slowly!) by gravity feed with the downstairs radiators often staying cold.
I have changed the pump (twice!) and the anti gravity valve (it doesnt stop gravity flow in the opposite direction!), and flushed the system. The system is gravity hot water, pumped ch and has a primatic tank, Potterton Myson boiler . I have bled the pump and spun the shaft too.
The only thing I have noticed is that shortly after the pump on the supply side there is a tee fitting which has a short vertical piece with what looks like a bright silver knurled knob on the end. Access is difficult and it wont turn. Is this a bleed valve and do you think that an air build up here is causing problems. The main supply pipe goes horizontal from 5cm below this and finally a with short rise to the upper level.
I am getting desparate for a solution and running out of ideas! Any help appreciated
when the ch works it works very well but on most occasions the water isn't circulating properly and the system ends up heating up (badly/ slowly!) by gravity feed with the downstairs radiators often staying cold.
I have changed the pump (twice!) and the anti gravity valve (it doesnt stop gravity flow in the opposite direction!), and flushed the system. The system is gravity hot water, pumped ch and has a primatic tank, Potterton Myson boiler . I have bled the pump and spun the shaft too.
The only thing I have noticed is that shortly after the pump on the supply side there is a tee fitting which has a short vertical piece with what looks like a bright silver knurled knob on the end. Access is difficult and it wont turn. Is this a bleed valve and do you think that an air build up here is causing problems. The main supply pipe goes horizontal from 5cm below this and finally a with short rise to the upper level.
I am getting desparate for a solution and running out of ideas! Any help appreciated