Central Heating - Add a zone for underfloor heating?

[LocoBlade]

Hi All

We're having a single room ground floor extension built in the spring and would like wet underfloor heating rather than a radiator. Our current central heating comprises of a Vaillant condensing system boiler (slightly over-specced when we fitted it ~5 years ago so has sufficient capacity) using a single zone heating and hot tank circuits in an S plan configuration I believe.

To add underfloor heating for a single room (~4m x 4m) I'm guessing we'll need to add a new zone which can then be controlled by a separate room stat something like this, would that be correct?



The boiler is mounted on the wall of an existing single storey utility room extension backing onto the new extension so its all nice and close for plumbing in. My thinking at the moment would be to install the new zone valve and underfloor manifold in the loft above the boiler where the boiler outlet pipe already runs, rather than having the manifold at floor level. The underfloor piping would then actually connect to the manifold at ceiling height and run inside the wall down into the floor like this, does anyone see an issue doing that?



cheers

Edited by LocoBlade on Thursday 26th January 08:15

[LaserTam]

I have no technical knowledge to add to this, only that yes, get the UFH on a separate zone. Unfortunately I didn't seek advice, nor received any from the builder/plumber and as a result my extension was just added to the existing circuit from the boiler. As a result, whenever the UFH is drawing heat because stat is saying it needs it, the rest of the radiators in the house also heat up (TRVs help, but still not ideal). I have found that the UFH really just needs to be kept at a constant heat as the time to heat the room is far greater than standard radiators, so all my rads are getting heat most of the time during this colder weather.

Its my one biggest regret when we had the extension done.

[Andehh]

Everything you posted looks fine, and is the way we did it. Manifold in the airing cupboard with the rest of the heating kit. Yes you will need a separate pump/manifold & thermostat for the UFH so that it itself can control the flow/temp of that zone.

You can spend a fortune on a thermostat & have it wireless etc, or hardwire through to the manifold/pump controller unit.

Where ever you buy the UFH kit from, will be able to advise on what thermostats they offer.

Edited by Andehh on Thursday 26th January 08:32

[LocoBlade]

Thanks for the confirmation about not having it on the same circuit

Regarding control, the plan at the moment is to get a system that can be controlled via a regular room stat then add it as a zone to our Hive system.

Any thoughts on running the UFH pipe from the loft of the existing extension rather than having the manifold at floor height in the new extension, how flexible is the pipe for going round 90 degree corners going from the wall to the floor (assuming elbows / joints are a no-no)

Edited by LocoBlade on Thursday 26th January 08:26