Supply and return line to manifold plumbed in back to front but UFH has worked for 13 years! Is it possible?

[GJW]

Hi all,

 

My UFH has been working for 13 years but in the recent cold snap I noticed that the ground floor was not getting as warm as normal. I've never really had to pay the UFH much attention as it has been working since I moved in to the house 7 years ago.

 

I have UFH with a direct feed to the manifold from a gas fired boiler together with HW heated using a thermal store. 

 

My manifold is a GIacomini R557. 

 

Trying to solve the problem, I opened and closed the thermostat valve a few times and noticed the temperature gauge on the manifold changed from 34 to 40 degrees. I suspected debris in the valve or a faulty valve and so have ordered a new valve. There was a couple of small leaks from the manifold pipework and so after changing the valve and fixing the leaks I will bleed the system. If that doesn't work, I guess the pump might be on it's way out but wanted to check the cheaper options first!

 

While looking at the problem I noticed that the return line to the boiler the temperature of the pipe was 50 degrees and on the supply pipe it was 35! The flow upper side of the manifold is cooler than the return lower side of the manifold.

 

I can't follow the pipes to know for sure but it looks to me like it has been plumbed in the wrong way round! I can't think of any other reason and having talked with Giacomini they have said that the system would work if it was plumbed in back to front although not as efficiently as it should do.

 

I was hoping someone might be able to help, by suggesting another reason for the return being hotter than the supply or if they have seen it plumbed in like that before for a specific reason.  

 

It does look pretty straightforward to swap over the pipes but as its been working for so long I'm a little hesitant!

 

Any advice or help will be much appreciated, thanks!

 

 

Edited January 15, 2021 by GJW

[ProDave]

Post a picture of your manifold, they vary so much, for others to comment on before you change anything.

[PeterW]

Can you mark which pipes you think are flow and return and which is hottest ..?

 

And a better photo of the pump ..? Thanks

[GJW]

Many thanks for the very quick replies.

 

I believe the pipe underneath the red handled valve on the right hand side is the return to the boiler, This is about 50 degrees.

 

On the left hand side underneath the thermostatic valve with the white head I believe is the supply, about 35 degrees.

[MikeGrahamT21]

Why oh why is there half a plastic drinking bottle cable tied onto the pipework? ?

[LA3222]

Looks like its got some tasty watter in the bottom of it?

[PeterW]

The thermostat valve will be working in reverse...! So if you turn it down (ie cooler) then the top sensor will see warmer water and it will try and compensate. 
 

It’s not that difficult to fix but you would need to move the wiring centre from the right. 
 

The manifolds are modular - looks like that has a leak too so a good time to fix the leak - and you can essentially drain it down, undo the pump set and swap it to the other end using the same fittings. You would probably want to clean all the joints up and use something like JetBlue on all the joints as they are older and also look to be brass, and that would allow you to correctly install the pump to the right and the return to the left. 
 

It’s a half days job for a competent plumber. 

[GJW]

?? no point in repairing leaks until my new valve comes and I've decided whether to swap over the pipes!

[GJW]

5 minutes ago, PeterW said:

The thermostat valve will be working in reverse...! So if you turn it down (ie cooler) then the top sensor will see warmer water and it will try and compensate. 
 

It’s not that difficult to fix but you would need to move the wiring centre from the right. 
 

The manifolds are modular - looks like that has a leak too so a good time to fix the leak - and you can essentially drain it down, undo the pump set and swap it to the other end using the same fittings. You would probably want to clean all the joints up and use something like JetBlue on all the joints as they are older and also look to be brass, and that would allow you to correctly install the pump to the right and the return to the left. 
 

It’s a half days job for a competent plumber. 

 

Definitely will be fixing the leaks at the same time. 

 

You can't see in the photo but there is a connecting piece on both the supply and return line 50 cm from the manifold. Could I just undo and swap over the pipes rather than rearrange  the manifold?

[PeterW]

Yes that’s fine - can’t see that in the pics !

 

Those grey fittings look like the older poor quality ones too - may want to consider swapping things for Hep2O. 

[GJW]

3 minutes ago, PeterW said:

Yes that’s fine - can’t see that in the pics !

 

Those grey fittings look like the older poor quality ones too - may want to consider swapping things for Hep2O. 

 

That's a worry about the pipe fittings, there's a spagetti junction of pipes, elbows and connecting pieces at the boiler and that's only the ones I can see!

[PeterW]

Ok so disturb the minimum amount possible and just change it where you can get to it. You could easily swing a pipe behind the current manifold from the bottom of the “return” and use the other existing elbow to connect up so that would mean you only need to re-pipe the flow. 

[GJW]

Many thanks for the advice, much appreciated.

[RandAbuild]

Here's ours:

[GJW]

That looks a tidy install and much more space around it than mine which is crammed into a the eave of a roof space!