Hi all just changed the pump on my fully pumped system it was a like for like pump. System has 2 zones upstairs and down stairs. Turned it on pump works fine and upstairs works fine but downstairs doesn't come on at all . I opened the downstairs em valve manually but it still won't come on! In fact ho t water up to the valve cold beyond! Taken the Honeywell mechanism off and turned the valve with my fingers it moves freely but won't allow got water to flow? I live in a very soft water area (old pump Was fairly clean inside) My question is can these valves really block up inside? It's a very old system 30 ish years . Any help please thanks in advance
Electrical mechanical valves central heating
D
Deleted member 267285
Valves can block up, but unlikely from the work you’ve carried out (unless of course you’ve disturbed anything). Have you got rid of any air, or was it just isolation valves turned off at pump?
Hi many thanks for getting back , air in the system could be a problem I guess, So I drained down the system from a valve at the lowest point in the system in order to install the new pump. (I am not an expert of course ) The system refills when I turn the water back on. I have bled all radiators and gone back to the drain valve and checked that water comes out rather than air. When I turn off a working upstairs radiator it goes off as expected! The pump was installed the same as the previous pump. (I must stress that the system has worked fine for 30 years) The pump installs upside down (to copy the previous pump) ie the label is upside down. Again thanks to all (Happy Christmas)
The orientation of the label doesn't mean anything,close all working radiators and try to force the heat through the non working ones
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Some suggestions:
Take a picture of the pump and the settings its on. Make sure you show the arrow
Take a picture of anything else thats been changed during your recent work.
Modern pumps are different than the old fixed speed and old systems don't like the new variable speed.
Air takes ages to remove sometimes.
Was your tank dirty? You may have washed muck or sludge somewhere it shouldn't be.
I'd say to drain it back down and flush your rads out whilst you can. The crud that builds up in them really gooses the system.
Take a picture of the pump and the settings its on. Make sure you show the arrow
Take a picture of anything else thats been changed during your recent work.
Modern pumps are different than the old fixed speed and old systems don't like the new variable speed.
Air takes ages to remove sometimes.
Was your tank dirty? You may have washed muck or sludge somewhere it shouldn't be.
I'd say to drain it back down and flush your rads out whilst you can. The crud that builds up in them really gooses the system.
So I re drained the system the water was clear no bits in it. Re filled with all em valves open bled the radiators still the same problem the house has 3 floors an em valve for each plus one for the hot water. So in the picture directly opposite the pump is the middle floor which works fine. On the right of the H is the top and ground floor. The top floor works very weakly and the ground floor lower right of the H not at all. Awaiting your ideas thanks !
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Pump should be pumping downwards. Have you checked the air release valve on the end of the up leg? Unlikely anything has blocked up whilst you changed the pump if it worked before. What was the reason for changing the pump?