Underfloor heating advice needed

We did put the electric matting in a couple of properties in the bathroom. With average thickness tiles,it seemed pretty pointless imo for what it was doing. Just took a bit of the cold feel out,but not much more.

Slippers are a thing… Just sayin’.

15+ yrs ago we lived in a flat in Oxford that had underfloor electric heating.

Each room had a wall mounted 'stat with one buttom to program and operate the system, was a total pita to use and adjust.

Never noticed as i waked around in slippers.
Mrs liked the warm floor tiles in the bathroom.

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Yeah I think I’ve made my mind up, when we have the bathroom and en suite done we’ll have heating under the tiles, but I’m not going to bother in kitchen and dining rooms.

A mate has electric ufh in an extension, he never switches it on as it’s too expensive to run. We read similar and quickly discounted it.

Continal is a water based system we looked at. We went for Wundatherm in the end as a local installer recommended it. Its retrofit so you dont have to dig up the floor. You lose maybe 3cm in ceiling height. I can’t really comment on running costs yet. We put £850 of heating oil in the tank in November and it hasn’t run out yet. The ufh has been on to keep the builders warm and is set to come on when the thermostat drops to 12.

It was relatively easy to fit.

I’ve read that water based UFH is the way to go if you think you might ever come to rely on a heat-pump. But that also works best if your house is massively well insulated and if you’re there the whole time, as it’s not really designed for being cool (zero power requirement) while you’re at work and then warm in 20 minutes when you get home, which fossils are (were ?) really good at.

I have installed water based UFH in 2 homes now (kitchens and conservatory)

The water based version (v the electric) is more expensive to install, but less expensive to run (if run alongside radiators using a gas boiler). The extra initial cost comes from installing a manifold, pipes, laying screed, etc.

Also, even with guidelines, the spacing of the pipes, depth of screed, etc. isn’t an exact science. It depends on each rooms insulation.

Plus, it it ever fails, it could be costly or impossible to fix. The whole block of flats where my wife grew up had underfloor electric heating. They all failed, and electric storage heaters had to be installed.

So, as commented above, I’ve found it : slow to heat up and overshoots a lot (especially in kitchens where the doors to the garden and rest of the house are constantly used and open).

I would install radiators in future, lower cost, easier to maintain, warms the room up more quickly.

The best tip I can give you (especially with ground floor tiles) is to put in a layer of insulation under the tiles. This will stop the cold floor tile effect and the floor will feel much more comfortable. The thicker the better, but even 20mm is a very good start.

It was already in our house when we bought it. A water system in lounge and hallway. The rest of the house has radiators.
It takes a long time to heat up and is relatively expensive to run. I wouldn’t fit it myself I’d go for radiators. The lounge is always cooler than the rest of the house.

I feel like from a lot of the comments, users are expecting to use the system like traditional radiators. Good luck with that.


Retrofit water based ufh heats up quickly and cools down quickly, because its only a few cm below the floor. It loses maybe 10% of the heat downwards.

regardless, you still have a massive thermal area/mass so constant, low flow temps are the order of the day.


I think that the thermostats are probably really important. My mum’s has a zoned system, but the thermostats allow a huge overshoot - set them to 20 and it’ll turn on when it goes down to 16 and then off at 24 degrees. Unfortunately then it overshoots to 30 or more!

I don’t know if modern thermostats are capable of adjusting to this overshoot - I think that they should be. But as it stands, she has to manually control the heating, which is absurd.

Nest/Hive have excellent tolerances ime, they also have settings to compensate for the type of heating system being used.

Yeah my Hive is excellent at temperature control, it keeps it within a fraction of a degree of the desired temperature. Really looks the way to go if you want underfloor systems.

Overshoot is mainly caused by too high a flow temp coupled with a high flow rate.

Comments about it being an inexact science is totally bogus. It absolutely is an exact science. The installation of it by bell-end builders is absolutely not an exact science.

Some thermostats are gash tho and positioned wrongly which doesn’t help.

If electric is used then you could control the overshoot by using the timer to compensate perhaps?


It’s also worth checking behind the thermostat if you can be arsed. Quite often there is a fucking massive hole for the wire and if a cavity wall you get colder air from the void confusing the stat.



At work we used to use PID control as a starting point. In a continuously running system you can tune them to get the desired balance between response delay and overshoot.

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Thanks. It’s electric, though, so one easy fix is gone.

The thermostats are clearly rubbish - as you twist them you can tell when they switch, and these have huge gaps between on and off. It really is about ± 4 degrees, which is crap for anything let alone underfloor.

She’s going to move this year, so it’s not worth doing much tbh. Everyone in the block of flats (built 2009) has the same issue, nobody can make it work well.

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