Underfloor heating-should floor feel warm?

[BigBirthdayGloom]

We're having a rubbish time at the end of a building project and the latest thing is that we fear the underfloor heating doesn't work. We have asked the builder to prove that it does. He claims that basically we wouldn't feel warmth on the floor, only in the air and that it is working.
I currently have the thermostat up to 26. The rest of the house's radiators are pumping out heat and it is roasting. The kitchen remains at 17.5 and I can feel nothing underfoot. I rang (paranoid) an underfloor heating company and they said the floor should feel warm to touch although the air may take a long time to warm up.

Could the builder be right? Could I have a cold floor and the underfloor heating be working?

We installed ufh under really thick flagstones, we were prepared for the fact that it might just take the chill off them rather than actually be warm underfoot. In fact it is toasty warm. Your builder is talking bollocks.

Can we have an update OP or do you still have the plumber under house arrest?

No show from plumber today. The builder rang at three to say the electrician would be in tomorrow bright and early to check whether the controller works and if that didn't help then he'd get plumber. Makes sense and a house arrest would have been awkward tbh .

I feel more relaxed thinking it could well be the controller because a new controller does not involve ripping up the floor. That would cost more than we have left to pay the builder, so I'm guessing wouldn't happen and would also be more than I could bear after umpteen delays. Thanks for asking! Once again, mumsnet keeps me sane (ish)

And I have a couple of other questions for the electrician. I will make him a lovely cup of tea, then grill him. No, not literally!

Have you tried turning all the radiators off to see if they are affecting the thermostat. If the room temp is already ok due to the radiators the UFH won't kick in.

Also, check if you've got any flow meters on the manifold to see if you're getting any flow through the pipes at all.

UFH works best at a low temperature and the surface temp of the floor is often not more than 40 deg C so shouldn't feel toasting just slightly warm.

And UFH gives off radiant heat so does not directly heat the air, only indirect.

Oops, just googled and the max recommended surface temperature is 29 deg C.

I like the thought that you will be holding him hostage! Make sure you really understand ow it all work - all the controls, where tey are Where the instructions are. To be honest - heating that works well but people who do not know how to operate controls are a frequent call out problem in autumn.

I like the electrician-I might feign ignorance so he can stay longer to explain just once more . Can't stand the plumber. He'd have been a better choice for explaining although useless if something needed fixing. Which is part of the source of the nervousness. He, erm, forgot to put in any water supply to the kitchen. I saw the pipes under the floor but I really hope he didn't forget anything there.

So, electrician came and although there's apparently some problem with one of the sets of pipes...the floor is warm!!!! Very relieved indeed.
Piglet John or other expert, there are four valve things where the pipes go to circulate the hot water. One of them has been continually pumping up and down like some icu equipment. Is that okay? I believe the plumber is coming to look at it.
Also, mumsnet jury, if you'd refused to pay until heating was proven to work, would you assume warm floor=working= pay. Or d'you think we should hold fire until plumber has fully explained its use?

Hold off on paying until you are completely satisified.

We used to live in a property with thick floors, our underfloor heating took about 24 hours to heat up and we would keep it on all the time (at about 16 degrees). It definitely felt warm (even hot) underfoot though once it was heated up.

Part of the job is making sure the client knows what they are using. So unless you are being particularly dense (its been explained clearly and simply a billion times and you still don't get it) they haven't completed the job so shouldn't get final payment.

I'm loving the warm patches on the floor Explained - a bit by the electrician this morning but not properly. Also, I'm going to push for a second thermostat as I'm not happy with the rest of the central heating being radiator thermostats only. Two thermostats are on the plumbing spec so two stats it's going to be.