Wet underfloor heating - what is the difference between brands

[Ianf]

Hi I have just joined the forum today after looking at some of your old posts and you seem a very helpful lot!

I'm sure my questions have been asked before but I haven't been able to find the answers on here.

I am installing wet underfloor heating to an extension apx 30m2 to a kitchen. This will run off a Vailant Ecotec combi boiler. The rest of the house is on radiators split in two zones, upstairs and downstairs. I was planning to split off again to a 3rd zone for the underfloor heating.

The problem I am having is deciding on the make of kit and pipe.  I started off looking at the popular brands of JG Polypipe  HEP20. I then started looking at other and some cheaper brands. I dont wan't cheap rubbish but dont want to unnecessarily  pay for a make. My first concern was the pipe under the floor as this is I feel the most important as this cannot be easily changed. It appears that some of the big brands use PB pipe and some of the lesser known ones seem to use multilayered pipes come with aluminium. Why is this? what is the best? I have also seen that PB has been banned in America due to the chlorine causing leaks. So why do we not have the problem here - or will we in the future?  I have seen comments that this was just the fittings. 

I stated looking at the Wunda underfloor kits after some comments on here, lots of happy customers on here. I phoned the technical help line to ask a few questions, they were very helpful but I was a bit concerned that the mixing valves were made by themselves and not a known brand such as reliance.- is this a problem I asked myself??  I was also surprised to find the pipe is supplied from either China or Europe- again should I be concerned with china?? I have seen comments on here saying china does not always make rubbish like the iPhone comment depending on your view.

With that I then looked on to Emmeti, nd came across a T3 kit that appears good - a nice video showing how the blending process works and the temperature probe.  But, why is there more kit involved in this unit over most other brands? is it unnecessary or is it important to make sure the pipework is not overheated?  There also is the question of the pump, after reading again more comments on here it would appear the Wilo pumps are favoured due to sounds reduction. The Emmeti has a grudfos pump.  I sort of gave up the will to live then after going full circle and looking at polypipe again.

I keep trying to tell myself this is just a small extension and most people on here are building new houses with multi zones, what am I worrying about!! 

So some advice would be appreciated to help me make my  decision. Cheers

 

[Temp]

Welcome.

 

The material the pipe is made of can differ. Some use PEX and others I think use polybutylene (spelling?). In the USA the later has/had a bad reputation but seems ok here. 

 

Any pipe used should have an oxygen barrier  and be pressure tested before you pour the floor screed.

 

Make sure to put enough insulation under it. In a new house I would go for at least 100mm of PIR and others put 200mm of EPS.

 

Edited March 6, 2021 by Temp

[Temp]

The aluminium is just one form of oxygen barrier but it may also help locate pipes later if you need to drill holes.

[Ianf]

Thanks for your reply. It's a bit of a minefield to know what to go for. I have 140mm celotex down so hopefully should keep heat in.  I think I'm going to go for the pert al pert and the emmeti t3 pump and manifold. Good idea about the aluminum, it should make it easier to detect. Cheers