Is my UFH piped in correctly? (With photo)

[StevenW]

Hi Guys,

Quick question for you,

I have just had my underfloor heating piped into the main circuit by a plumber. I have not used him before.

My setup is a Sealed system, Convetional boiler, S plan plus with 3 zones. 2 heating/ 1 DHW.
The UFH uses a an RWC combined thermomix valve/pump assembly.


The flow that supply's the UFH setup has been Tee'd off before the main central heating circuit pump.
Is this correct? It was not like this previously and all schematic diagrams I have looked at show the flow branching off to the UFH zone AFTER the pump, as like the other 2 zones.

Last night, we had the UFH heating on and the other 2 zones off. The boiler seemed noisy and the system pressure was up over 2 bar.

As I can see it, when only the UFH zone is on, and no demand from the other 2 zones, the Auto bypass valve is going to be constantly forced into bypass by the main pump.
Also, as the flow to the UFH is branched off on the intake side of the main pump, the pressure differential between the flow and return of the UFH is likely to be higher on the return side.

I am an aircraft engineer by trade, not a central heating engineer. So any advice and information would be greatly appreciated.

Many thanks in advance!

Steve.


p.s. Ignore the temporary wiring in the photo please!

 

[StevenW]

 

[kozak1968]

On a conventional system it should be boiler,pump,auto bypass, then zone valves. It looks like your manifold does not incorporate a pump. A seperate pump has been fitted. The zone valve for the u/f is normally before the u/f pump.

 

[StevenW]

Hi Kodak,

Sorry for poor photo quality.

That black blob to the left of the manifold is the circulation pump for the UFH. See the cable going to it.

It uses the combined Reliance Thermomix valve/pump assembly. Quiet common I believe.

There is a zone valve also before this UFH pump. There is o problems with this part of the set up.
It's just the take off for it from the main heating loop, looks to be the wrong side of the pump.
And from what you have said in the first part of your reply, it is wrongly done.

 

[kozak1968]

The tee for the u/f circuit flow should be after the grundfos pump. Sorry I couldnt see the manifold pump properly.

 

[Chalked]

Hi
Not sure on pipe connections on a Worcester. But is that pump on the return?

 

[StevenW]

Flow on the left, Gas supply in the middle, Return on the Right hand side.

That T is on the flow outlet from the boiler but before the main pump. Which I think is incorrect?

 

[Chalked]

Flow on the left, Gas supply in the middle, Return on the Right hand side.

That T is on the flow outlet from the boiler but before the main pump. Which I think is incorrect?

You are correct. It basically has two returns! Will need altering.

 

[Stanios]

O dear.. Had UFH put in at a job we put boiler + cylinder. God the guy was absolutely clueless. Wired pump into permament live, manifold was screwed in well p*ssed on the wall. Looks like underfloor heating sector doesnt attract the brightest of minds..

 

[leethegasman]

Yes you are correct your system has been piped up incorrectly.your pump from the boiler should be pumping to the zone valve on the ufh heating as well,the pump on the underfloor heating only circulates blended water around the ufh loops.you still need to pump water to the ufh blending valve.