Unvented composite valve (reliance) query?

[macka09]

Hi all. I seen an install today of a direct unvented cylinder which looked odd and just wanted some advice on it please. On a composite valve am I right in thinking, there’s a 22mm cold inlet, 2 balanced cold outlets and a prv??

 

[ShaunCorbs]

expansion vessel port normally after the balanced

 

[macka09]

expansion vessel port normally after the balanced

I thought that was the case but I’m being assured that the 22mm connection on the side can be used for a balanced cold as well as a balanced cold out the bottom of the valve??

 

[townfanjon]

Never have two balances, if it got the plastic plug in it thats for the ex vessel , could do with a pic or manufacturer

 

[ShaunCorbs]

I thought that was the case but I’m being assured that the 22mm connection on the side can be used for a balanced cold as well as a balanced cold out the bottom of the valve??

it could be but no scv in the end so would require one

 

[macka09]

That’s the set up guys!

 

[Karl]

I thought that was the case but I’m being assured that the 22mm connection on the side can be used for a balanced cold as well as a balanced cold out the bottom of the valve??

Balanced cold only any good before the check valve, if you blow back through the valve (opposite direction of flow) the port your getting air through is for the expansion vessel and the other will be for balanced cold

 

[ShaunCorbs]

That’s the set up guys!

View attachment 34171

why does it reduce to 15mm

 

[macka09]

why does it reduce to 15mm

It goes off to a kitchen and bathroom.

 

[macka09]

Balanced cold only any good before the check valve, if you blow back through the valve (opposite direction of flow) the port your getting air through is for the expansion vessel and the other will be for balanced cold
View attachment 34170

View attachment 34169

This a different valve to what’s in the photo mate.

 

[Karl]

This a different valve to what’s in the photo mate.

I’m aware of that I was posting that whilst he posted picture so I didn’t see until after, anyway I was showing as an example they still work the same

 

[ShaunCorbs]

It goes off to a kitchen and bathroom.

meter inlets

 

[macka09]

meter inlets

I don’t actually know tbh with you. I was concentrating on the vessel set up and the 2 balanced colds if I’m honest. Have any of you seen a combi valve with 2 balanced colds?

 

[Scott_D]

Balanced cold needs to be before the check valve or you could get hot water flowing back from the cylinder

 

[macka09]

it could be but no scv in the end so would require one

Single check valve ??

 

[chris watkins]

Are we talking about the red item or the blue ?
Cos I see only one balanced cold port (blue). The other is a manifold for the cold water (red).

 

[Karl]

View attachment 34172 Are we talking about the red item or the blue ?
Cos I see only one balanced cold port (blue). The other is a manifold for the cold water (red).

This is what I couldn’t grasp, not sure what he was trying to ask. I think he means the cylinder side of the combination valve but don’t get why you would want to do that anyway when there’s a balanced cold there

 

[ShaunCorbs]

Single check valve ??

Yea else hot water could flow backwards

Pressure reducing valve
Balanced take off with internal check valve
Balanced take off
Single check valve
Pressure relief valve

Would have to go like that so separate prv and relief valve needed

 

[Tim S]

All the inlet control groups I've installed have only had one balanced cold outlet...never come across one with two

 

[dan_the_plumber]

Have you got your G3 certificate? Maybe you could do with an update

 

[townfanjon]

Unless theres another picture I cant see , that set up is fine .