HELP PLEASE!!! central heating problem

Alex1983

Fuse spur LNE to new timer LNE.

New timer
1 HW OFF - grey on the y plan valve
2 Nothing
3 HW ON - cyclinder stat COMMON (sounds like your brown)
4 CH ON - white on the y plan

Cyclinder stat calling (sounds like your blue) into connector block with ORANGE y plan and boiler LIVE and pump LIVE.

I would think the earth cable (someone has used wrong colour cable) goes to the cyclinder stat is SATISFIED and will need to go to the GREY on the y plan valve but you need to check inside the cyclinder stat to make sure it goes to a live connection and not a earth

tonyhayfield

i take it neutral and earth from pump, boiler and y plan valve all go to the fuse spur neutral & earth

Alex1983

Sorry I didn't say, yes that's correct.

tonyhayfield

Fuse spur LNE to new timer LNE.

New timer
1 HW OFF - grey on the y plan valve
2 Nothing
3 HW ON - cyclinder stat COMMON (sounds like your brown)
4 CH ON - white on the y plan

Cylinder stat calling (sounds like your blue) into connector block with ORANGE y plan and boiler LIVE and pump LIVE.

I would think the earth cable (someone has used wrong colour cable) goes to the cyclinder stat is SATISFIED and will need to go to the GREY on the y plan valve but you need to check inside the cylinder stat to make sure it goes to a live connection and not a earth

thanks very much for that have re wired it to how you have said but the 3 port valve still clicks in the a/b position. and both heating and hot water are on when i only put hot water on??

Alex1983

What brand 3 port is it? It's possible that it is seized in mid position if it isn't seized then I think you will need to get someone who knows there system wiring to take a look.

If it's wired correctly then they will need to test with a multi meter to find out where the power is coming from. with hw on and calling from the cyclinder stat only there should only be power 240v on the orange. You most have power coming on the grey or brown as well which is making the y plan valve keep the heating on.

tonyhayfield

its a Honeywell v4073a motorised mid-position valve. its not seized as it closes off when no power, but for some reason when the water is on there is power to h/water on and heating on but the power to heating side comes on and off with each click

Alex1983

Did you check the cyclinder stat connections. Should have a common, calling and satisfied. Where do these connections go?

tonyhayfield

yes checked the cylinder stat has common 1 and 2 and the y/green was not earth but everything has been wired exactly how you said

Fuse spur LNE to new timer LNE.

New timer
1 HW OFF - grey on the y plan valve
2 Nothing
3 HW ON - cyclinder stat COMMON (sounds like your brown)
4 CH ON - white on the y plan

Cyclinder stat calling (sounds like your blue) into connector block with ORANGE y plan and boiler LIVE and pump LIVE.

I would think the earth cable (someone has used wrong colour cable) goes to the cyclinder stat is SATISFIED and will need to go to the GREY on the y plan valve but you need to check inside the cyclinder stat to make sure it goes to a live connection and not a earth

Alex1983

Only thing you could try is swap your cyclinder stat cables around, leave common as it is but change calling and satisfied around. If that doesn't fix it you need to get someone to carry out voltage tests to see where it's getting it's power from.