Mixing ufh electric systems (ditra, prowarm etc) - small kitchen ufh

[gambo]

I'm tiling kitchen and am expecting the floor to be colder in winter than it it's with LVT, so I want to put around 1.5-2m2 of electric ufh with an output of roughly 150W total. The idea is that it will be nicer to walk on warm tile but the kitchen will keep its radiator as the main source.

Firstly, lots of different systems and I like ditra heat mat as it give a (very) little bit of insulation. Next I can get ditra heat cable but do I need thermostat from ditra too or is everything so simple in design that I can put a Mapei heat cable into ditra mat and link it with prowarm thermostat?

Given I'm heating tiles not the room how radiant the heat from the cable is? Can I cover 4sqm of kitchen with a 150W cable (normally intended for 1-1.5sqm) and still expect nicely warm floor?

[MikeGrahamT21]

You can use any UFH thermostat with heating mat/cable, as long as it’s rated more than the load you are wanting to run, which for your area will be every one in existence.

The worse the insulation underneath the floor, the less heat you’ll get out of it, but any heat which does go into the tiles which radiate into the room, it’ll certainly make a difference but how much depends on your insulation levels.

be warned as well, it can be quite expensive to run.

The cable itself isn’t 150w/m2, it’s the spacing of the loops that determines that, so by making 2m2 worth of cable span 4m2 your just making it 75w/m2, which will need some serious insulation to make a difference.

 

the other side to look at is how much you want the warranty, mixing systems will most likely void any warranty 

[gambo]

Insulation level is low, standard late 80s build. That's the reason the radiator stays and the ufh will be warming up the tiles rather than heating the room.

Any recommendations for cables, uncoupling mat, thermostat?

 

[Nickfromwales]

10 hours ago, gambo said:

Given I'm heating tiles not the room how radiant the heat from the cable is? Can I cover 4sqm of kitchen with a 150W cable (normally intended for 1-1.5sqm) and still expect nicely warm floor?

You can expect you left foot to be warm and the right cold. DO NOT do this! Just buy a 50w/m2 kit on a mat and do it properly plz!!!

[Nickfromwales]

6 hours ago, gambo said:

Insulation level is low, standard late 80s build. That's the reason the radiator stays and the ufh will be warming up the tiles rather than heating the room.

Any recommendations for cables, uncoupling mat, thermostat?

 

If you want a brand, then Warmup for cable/mat and a very good controller. The 3ie and 4ie (iirc) are good, with learning algorithms to predict how long it takes to get the floor to the desired temp at the desired time, so if it takes an hour to get to the temp you want at 07:00, it'll learn to switch the floor on at 06:00 etc, same for turning off (again iirc). Speak to their technical guys to get more clarity.

[gambo]

I bought ditra heat duo and their cable, no thermostat yet. I may have not done enough research but I was expecting a short section of unheated cable to deal run it under fixings. Any issue with running 60-80cm of cable under cabinets?

[gambo]

I've found the cold cable! Is it possible it's 3-4m long for a 12.07m version?

[gambo]

On 17/08/2025 at 23:34, Nickfromwales said:

If you want a brand, then Warmup for cable/mat and a very good controller. The 3ie and 4ie (iirc) are good, with learning algorithms to predict how long it takes to get the floor to the desired temp at the desired time, so if it takes an hour to get to the temp you want at 07:00, it'll learn to switch the floor on at 06:00 etc, same for turning off (again iirc). Speak to their technical guys to get more clarity.

It's all quite confusing if someone doesn't have experience. I was hoping to just run the cable, tile and think about the rest later on. However, I've just realised no thermostat means not temperature probe. Given what I've read I may run two probes but need to get it asap. Can I use any ufh temperature probe with Ditra heat cable? e.g. I can get JG sensor probe from screwfix, then I may go with Warmup thermostat if it's better than schluter.

[Nickfromwales]

2 minutes ago, gambo said:

It's all quite confusing if someone doesn't have experience. I was hoping to just run the cable, tile and think about the rest later on. However, I've just realised no thermostat means not temperature probe. Given what I've read I may run two probes but need to get it asap. Can I use any ufh temperature probe with Ditra heat cable? e.g. I can get JG sensor probe from screwfix, then I may go with Warmup thermostat if it's better than schluter.

Yup. I always fit 2x thermo probes if I can't install the conduit to change them out at a later date.

 

3 minutes ago, gambo said:

I may go with Warmup thermostat if it's better than schluter.

I'm not able to advise as I've never used Schluter, so it may be better! Have you a link to the one you are considering, or at least just get the spec sheets alongside each other for comparison.

 

The benchmark for a good unit is a bit of self-learning for setback.

[Nickfromwales]

@gambo

 

[gambo]

32 minutes ago, Nickfromwales said:

@gambo

 

Do you know if I can buy any probe? Eg JG from Screwfix?

If I need to buy schluter probes it will cost me £40 for two.

I want to go through manuals of different thermostats and see which one suits me first.