Care home UFH wired incorrectly

[Michael Groves]

I’m an electrician, a plumber has asked me to look at wiring in a care home for UFH with a system boiler.
Only way to get it to work is run everything constantly.
The wiring center was a mess, i’ve rewired and now working as expected.
However, it appears to me there is an unnecessary valve. On the heating side there is a master valve (S-Plan), then behind this two manifolds with thier own valves. The master valve was wired to be constantly open.
I’ve rewired for it to only open when one of the UFH valves is calling for hot water.
I’ve been told UFH was installed by one company and boiler by another. So I wonder if boiler engineer installed S-Plan, and UFH just fitted to this.
I can’t see any reason for the master valve (S-Plan). I’m gonna suggest to plumber to remove as I just can’t see any reason for it and I think this will simplify installation, what do you think, am I missing something.
To be clear I’m ignoring hot water in this post, that all works fine.

 

[Last Plumber]

Photographs might help if you have any?

 

[Michael Groves]

Photographs might help if you have any?

Unfortunately I’m not back for a while, but photos probably won’t help anyway as the installation is spread out across the property.
To put it another way, the installation has two valves in series. Is that normal with UFH?

 

[ShaunCorbs]

Zone valves wired in series ?

 

[Harvest Fields]

Thought you previous said you was a landlord and not a sparks.

 

[Michael Groves]

Thought you previous said you was a landlord and not a sparks.

I’m both.

 

[Michael Groves]

Zone valves wired in series ?

Plumbed in series. imagine;
boiler
valve
pair of valves each with UFH manifold.

I’ll try and post a diagram later if that does not make sense.

 

[Michael Groves]

Here's a brief diagram, hopefully this makes more sense than my text.
To recap, I don't see why you need a "Master Valve"

 

[Harvest Fields]

Are there rads as well as UFH?

 

[Michael Groves]

Are there rads as well as UFH?

No

 

[ShaunCorbs]

You sure it’s not a 3 port would make sense

 

[Michael Groves]

You sure it’s not a 3 port would make sense

When you say "3 port" I guess you are referring to Harvest Fields suggestion as opposed to a 3 port valve?

It would then make sense if this was the case. I will double check when I am back, but I was lead to believe there is only UFH.
If this is the case, do you agree the "Master Valve" is superfluous ?

 

[ShaunCorbs]

When you say "3 port" I guess you are referring to Harvest Fields suggestion as opposed to a 3 port valve?

It would then make sense if this was the case. I will double check when I am back, but I was lead to believe there is only UFH.
If this is the case, do you agree the "Master Valve" is superfluous ?

No it could be a 3 port zone valve or are you 100% it’s a 2 port

 

[Harvest Fields]

I am confused by what you mean by a master valve? Are there just 2 zone valves. If so you have to have these otherwise the under floor would only come on with the water and they will want the underfloor on by itself .

 

[Michael Groves]

No it could be a 3 port zone valve or are you 100% it’s a 2 port

Definitely a 2 port valve, 100% sure

 

[Michael Groves]

I am confused by what you mean by a master valve? Are there just 2 zone valves. If so you have to have these otherwise the under floor would only come on with the water and they will want the underfloor on by itself .

Master valve is my terminology as it governs the subordinate vavles, look at the diagram, it's in series with the manifold valves. The manifold valve triggers the boiler when any of the thermostats call for heat. All the thermostats are wired into a relay for this purpose.

 

[ShaunCorbs]

Remove it then

 

[Harvest Fields]

Could be an old valve or it could be for a heating circuit. You need to double check it is for the UFH only.

 

[Michael Groves]

I’ll double check again to be sure there is no third circuit, but otherwise I’ll unwire and leave manually open, then tell plumber to remove when he next drains.
Thanks guys,

 

[Harvest Fields]

I’ll double check again to be sure there is no third circuit, but otherwise I’ll unwire and leave manually open, then tell plumber to remove when he next drains.
Thanks guys,

You need to make sure that it is definitely open all the time and cannot close at all or it needs removing at the same time.

 

[RoryD]

Ditch it, it appears superfluous looking at that diagram.

 

[oz-plumber]

It may be wired in with the DHW valve.
When the DHW valve is opened - the valve in question might close.
May have been done to simplify the wiring?