Wet underfloor heating system

[MARIE1]

My underfloor heating is set at 21 on the stat but the floor area feels cold to touch. I was expecting to feel a little warmth from it. I have since discovered that my builder has laid a 30sqm pack over a 50sqm area. Is this as bad as it sounds? Thanks in advance

 

[Dotty]

If your builder has installed it it's probably worse.

 

[oz-plumber]

Unfortunately - Yes.
Were there any heatload calculations done?

Do you have any photos of the piping at the time of installation?

 

[Riley]

Sounds like an expensive error you can either get it redone or pursue "builder" to try and get some money off. Begs the question why they didn't use an experienced plumber. See so many poorly installed ufhs by builders who think it's just a case of throwing it in

 

[Worcester]

There's no such thing as a 30m2 pack... As ... It all depends upon the heat loss of the room, the designed flow temperature, and possibly the heat source.

Ask him for the heat loss calculations.

Old leaky buildings like the one I surveyed today, 150W/m2 house size 80m2 heat load 12kW
Then there's the new build we're working on 450m2 , 26W/m2 Heat load 12kW

The design and installations are completely different... (the first isn't suitable for ufh, the second we have to cool the house in the summer...)

What length of pipe did he install, how many loops, serpentine or snail,

What was the designed flow temperature for the underfloor heating?
Has he connected the flow and return the wrong way round?
Is the TMV on the manifold configured correctly?
Does the underfloor heating have it's own circulation pump?
Did he just tap off the existing heating circuits?
Are there in screed stats or just air stats?

 

[lame plumber]

Its a pity there arent more like worcester out there, too many doing things they dont understand! ps I dont touch ufh, as I know fa bout it