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Discuss Should UFH be nearly scalding at floor with Vinyl (LVT)? in the Underfloor Heating Forum area at PlumbersForums.net

Mr S

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Hi All.

I'm pretty sure the answer to the above is "no".

I've recently had UFH installed, with a mixture of porcelain (kitchen) and LVT (lounge). I have a mixture of neoStat wall stats but no floor probes. (I was never advised to get such). The UFH in lounge is sitting in Polypipe Boards and in scree in kitchen.

Now that we actually (post-heatwave) need the UFH, we've noticed that the LVT is "spongy" and almost too hot to stand on.

I assume this means the temperature is way too high? That, or there isn't enough substrate between pipes and LVT.

What's the best way to address this while ensuring performance (i.e. that it's still hot enough to warm the tiled areas). Should I ask the installer to reduce the temperature? Should I insist on lifting things up and fitting floor probes (which sounds painful)?

Many thanks in advance.
 

ShaunCorbs

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There should be a temp gauge on the manifold what's this set at also any pics of the manifold
 

ShaunCorbs

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Yes that's running way to hot 65 dc through the under floor way way too hot can cause problems for your floor

Get the people back who installed it

@Uheat – Jake
 
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Mr S

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Yes that's running way to hot 65 dc through the under floor way way too hot can cause problems for your floor

Get the people back who installed it

@Uheat – Jake
Thank you. One quick thing. Isn't 65 dc the input temperature (from the boiler) and 53 the temp going into the floor? Am I mis-reading things? (Of course, 53 dc may well still be too hot). Thanks again!
 

Chalked

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Turn the thermostat ( black knob that’s upside down) slowly, while the heating is on, until you get a constant 40 degrees. On the top dial. Then adjust each flow restrictor, until the return temp gauge reads around 7 degrees lower.
Takes a bit of time to do, but will work correctly.
 

Chalked

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So looks like the actuators are on manual. They should face the other way. Turn clockwise to put onto auto.
 

ShaunCorbs

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So looks like the actuators are on manual. They should face the other way. Turn clockwise to put onto auto.
Also doesn't look balanced
 
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Mr S

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So looks like the actuators are on manual. They should face the other way. Turn clockwise to put onto auto.
Hi. Just so I'm clear, because the heating is responding to the neoStats. What do the actuators do? Are they not being controlled by the wiring attached to the neoStats? Thanks
 

ShaunCorbs

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Apologies for not knowing the terms. "Balanced" how?

Thank you for your continued help.
Clear flow dials haven't been set either I think
 
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Mr S

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Clear flow dials haven't been set either I think
Are these the flow guages at the top? The red discs are dropping a few minutes after the heating comes on in each room, except for the third guage (which I think has problems). Thanks.
 

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Hi. Just so I'm clear, because the heating is responding to the neoStats. What do the actuators do? Are they not being controlled by the wiring attached to the neoStats? Thanks
Yes they are individually controlled by your stats. But they look like they are on manual. So will be on all the time any other room is on. Plus it’s set too hot.
 

Chalked

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Are these the flow guages at the top? The red discs are dropping a few minutes after the heating comes on in each room, except for the third guage (which I think has problems). Thanks.
Without knowing the loop sizes, adjust the restrictors to give 1-2 litres a min. That should give you a starting point.
Did you install yourself, or get a contractor in?
 
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Mr S

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Without knowing the loop sizes, adjust the restrictors to give 1-2 litres a min. That should give you a starting point.
Did you install yourself, or get a contractor in?
It was installed as part of a building project we've only just (so we thought) seen the back of. The builder's sub-contracted plumber did the job.
 

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