2-Port valve wiring?

[BigSi]

Hi all.

I’m currently wiring an S-Plan heating system (normally don’t get involved in this, but it’s been dumped on me).

I’m using a Honeywell DT90E room stat, and a Honeywell V4043H 2-port valve. In the room stat I’ve got A as live in, and B as live out (C not used, neutral not required), which is connected to the brown of the 2-port valve.

I’ve got 230v across the live and neutral of the valve, but the valve isn’t operating. The plumber who installed the system said to use A and C on the room stat, but what difference would this make to the supply of the valve? The DHW side works fine, it’s just the heating side that I’m having issues with.:banghead:

 

[grimysparks80]

Do you have a permanant live connected to the grey of the valve?

 

[BigSi]

Yep. And the orange to the on-demand on the boiler.

 

[mark1979]

faulty valve?

 

[Deleted member 9648]

Switched live to the brown of the valve opens it. Permanant live to the grey switches the orange when valve opens and brings in pump/boiler.If you have 230v on the brown/blue it should open regardless of other connections.

 

[grimysparks80]

agreed. Faulty valve. give it a tap with the lump hammer

 

[BigSi]

If you have 230v on the brown/blue it should open regardless of other connections.

Thats what I thought. But its also the fact that the plumber said to use terminal C (diagram didn't show any cables connected), so he knows what connections there are in the room stat.

What would happen if I reversed the brown valve cables, so the hot water demand operated the heating valve to see if it works?

 

[mark1979]

try swapping the valve heads. that will prove if its faulty

 

[grimysparks80]

I didnt think you could do that with honeywell valves. Arent they all one piece?

 

[mark1979]

sorry i meant completely swap them

 

[BigSi]

The valves are a bit of a pain to get too, so the changing wires over option might be better. Its just to see if the valves operate, if they do, then I think there might be an issue with the room stat?:icon9:

 

[mark1979]

are you not measuring 230v L and N at the valve already?

 

[grimysparks80]

As long as you get 230v between brown and blue at the valve when you turn the roomstat up you know its working right.

 

[robsparky1975]

Do you have 230v on the call for heat from the roomstat,you said a is common and b is call so 230v should be on the brown of the htg valve,measure in the wiring centre,is the neutral going to the valve(i have known a broken neutral before which shows the same problem,remember that as both oranges are connected to the switched live for boiler that you will get feed back from the other valve(90v or something even when hw is not calling.

 

[BigSi]

Thats what I don't understand? Ive got 230v across the brown and blue of the valve, when the stat clicks in, but the valve does nothing.....just sits there! Even when I manually open the valve using the little slide lever on the side, it doesn't bring in the boiler?