In uk.d-i-y, Mike Barnes wrote:
In uk.d-i-y, Toby wrote:
Can I take from the lack of response to this remark that everyone would
be quite happy with a heating system that only worked in winter when the
main house heating was on

Not sure how cold the floor will feel without any heat under it. My sister
has a slate kitchen floor onto screeded insulation, and right now this feels
refreshingly cool under bare feet. In an upstairs room it should be a whole
lot warmer. I can only suggest you get a couple of the slates out, let them
aclimatise and see how they feel.

Now that's what I call a sensible suggestion... right, I've got a couple
of flooring slates from the shed, have placed them on the bathroom
floor, and have asked SWMBO to try them out from time to time.

The experiment has run long enough to know that we definitely need some
sort of heating in summer.

For small area like that it gets expensive to introduce separate zone
controls so combining with the CH is the economic option. If UFH is needed
in summer then a separate zone is the only option unless all radiators can
be shut off. A pro job would involve a separate pumped and mixed loop
controlled by a zone valve.

I think that's where I'm going to end up. But for now the important
thing is to get the pipework under the floor. I can fiddle with the
controls in the airing cupboard later.

Thanks to everyone for their contributions.

--
Mike Barnes