Underfloor Heating, Vented or unvented?

[softlad1971]

I want to add some underfloor heating to my kitchen. This will allow me to get rid of the radiator and have more cupboard space.

My question is, Does the central heating have to be pressurized/unvented?

I have got a vented s plan with a 3 port valve and header tanks.

The only diagrams I have found with underfloor heating shows a pressured system.

Cheers Carl

 

[croydoncorgi]

Given that most UF systems use plastic tubing and O ring seals, you probably have to have a pressurised system to make it watertight (O rings tend to leak at LOW pressure). Apart from anything else, you want to be very sure that there are no corrosion products floating round the system - if a UF system blocks, that's the end of it!

Anyway, I've never come across a UF product which recommended anything OTHER than a sealed, pressurised system.