Underfloor Manifold 5mm valve problem

[mkdr30]

Hi all

first time poster, so be kind, even when you read what I've done!

I'm having a kitchen extension done at the moment, we've opted for wet/screed underfloor heating throughout.

Our builder and a plumber set the system up and its been commissioning for a couple of weeks (we are gradually increasing the temperature and are now at 55c).

The system seems to be unbalanced and patchy - cold here, warm there, and most annoyingly, the room is not warm. Have tried a few things, flushing the pipes for air, shutting down one circuit to force water through the other etc... The next thing i want to try is to reduce return flow to the boiler to force more through the pipes.

I have also made sure the isolation valves on the manifold (where the pipes enter the floor) are fully open....

and here in lies the problem...... I think I have over turned one of them anti-clockwise.

the valve is adjusted by using a 5mm allen key under a grub screw. So screw out, allen in, full turn anti-clock and... woosh! water straight out the top.

turned back clockwise and it stopped, but now the fitting is loose and wont tighten, no water but it sits atop the opening and spins. Almost like the thread is not connecting.

I've uploaded a pic of the setup inc the manifold and where the value in question is.


I'll sum up my question in one word... help?

Manifold setup for underfloor

• mkdr30
• 4 Feb 2015
• 1

red arrow show location of leaking iso valve,

 

[Crezzer]

What a god awful mess of a job that looks, theres no actuators on the manifold so I'm guessing its one zone, the manifold also looks like a cheap crap one as it doesnt seem to have any flow meters on it. The design paperwork should should have the required flowrate on it, I would get the installer back to set it up properly.

 

[mkdr30]

yeh 1 zone.

To be fair this pic was from day of install so it has been tidied up since.

The manifold is basic but I had noticed the lack of flow meters which is a pain.

I'm trying to figure out what to do about this valve - as per my opening post, its something ive caused by over lossening the key.

Just so when I get them back to look I know a bit about it!

Cheers

 

[Crezzer]

What is the make of manifold? Any paperwork with it?

 

[stardanny]

I don't know anything about underfloor heating, hate them.

But the pipes leading to and from is undersized and plastic pipes. Could these be reducing flow rate?

Daniel.

 

[mkdr30]

seems we've sorted this issue now.

I looked at the pump isolators and found one to be in the closed position. Had been that way ever since install nearly 10 days ago.

Valves in question have been scewed back in and capped off.

Hopefully will have a toastie warm floor by tomorrow.

 

[mkdr30]

I don't know anything about underfloor heating, hate them.

But the pipes leading to and from is undersized and plastic pipes. Could these be reducing flow rate?

Daniel.

they are standard 16mm screed underfloor pipes and have to be plastic to minimise the risk of leakage when encased by the screed. Pretty standard in ufh for years now.

 

[stardanny]

I don't know anything about underfloor heating, hate them.

But the pipes leading to and from is undersized and plastic pipes. Could these be reducing flow rate?

Daniel.

they are standard 16mm screed underfloor pipes and have to be plastic to minimise the risk of leakage when encased by the screed. Pretty standard in ufh for years now.

Not talking about that, I'm talking about the pipes from copper pipes to manifold in plastic and unsized.

Daniel.

 

[Dan Robinson]

Can you please change the picture for something that isn't making my eyes leak out of my ears.

 

[Agile]

Its normal to run UFH at a flow temp of close to 40 C.

I would expect that 55 C would risk cracking the concrete. As well as being uncomfortable to walk on in bare feet.

UFH rarely gives out enough heat for small rooms! It also takes about two hours to warm up. So it needs to be timed separately

Tony

 

[mkdr30]

Its normal to run UFH at a flow temp of close to 40 C.

I would expect that 55 C would risk cracking the concrete. As well as being uncomfortable to walk on in bare feet.

UFH rarely gives out enough heat for small rooms! It also takes about two hours to warm up. So it needs to be timed separately

Tony

The screed is calcium based and can handle temps of up to 65c flow.
The system is working properly now with an even surface temp of about 35c on the screed. Hoping this will result in a final floor temp of about 26-27c.

Assume you mean big rooms are difficult to heat with UFH? Well this one is 2 loops covering approx 35 m sq. If you build or renovate to 2010 regs, then there is no issue.

the system has been on for a few hours and the room temp is 23c and climbing. outside temp -3.

In regards your comment about timing, yes thats true - i'd say more like 3 hours to heat the screed up to temp. We'll be using a nest to control the heating and setbacks, running the system 24hrs a day.

 

[mkdr30]

I don't know anything about underfloor heating, hate them.

But the pipes leading to and from is undersized and plastic pipes. Could these be reducing flow rate?

Daniel.

they are standard 16mm screed underfloor pipes and have to be plastic to minimise the risk of leakage when encased by the screed. Pretty standard in ufh for years now.

Not talking about that, I'm talking about the pipes from copper pipes to manifold in plastic and unsized.

Daniel.

oh ok - yeh its 15mm plastic, but all seems to be running fine as is. I guess if they are problem its a easy job to swap out with copper in future. The manifold attachments are 15mm.

 

[mkdr30]

Can you please change the picture for something that isn't making my eyes leak out of my ears.

Apart from the untidy cabling in the pic (which has now been tidied) what offends you about it?

Genuinely interested, im the customer, not the fitter.

 

[Dan Robinson]

The pipe work looks awful - the mixture of plastic and copper etc.

The controls look cheap and nasty as well. I don't like to see regular zone valves on UFH due to them not being appropriate for long periods in the on position .


Just looks like something DIY - hope you didn't pay for it.