Underfloor heating temp sensors

Hi all,

I’m looking to go full Velbus both for lighting and heating control in an upcoming renovation.

We will be installing underfloor heating and instead of also using the air temp sensor/thermostat in the glass panels, many underfloor heating system measure the slab temperature via a 10k ohm floor probe, which I would like to do to get better efficiency by having more control over the system - knowing both air temp and floor temp.

What is the best way to integrate such a temperature probe into the Velbus system? For example Is this directly supported by the VMB7IN input module?

Many thanks



Welcome to the forum.

Indeed, a lot of systems use that method.

In Velbus terms, we have lots of options.

If you just want to set a threshold and never need to adjust it (remotely) you can put a simple digital thermostat in the slab, with a 10K sensor, that can either break the supply to the valve until the slab cools or signal an input of a VMB7IN, which would in turn force the zone thermostat into safe mode, until the slab cools.
(This way, you’ll see a padlock symbol for that thermostat)

For example -

There are hundreds of options



You can fit 2k sensors and connect them directly to an input of a VMB4AN, where you can do all kinds of things with the state / data, like set a threshold that forces the zone thermostat into safe mode.

(You can also log the temperature in platforms like openHAB)

I’m happy to supply some basic wiring plans outlining these suggestions.

May I ask where you’re based in the UK?


Thanks a lot for getting back and likewise for providing some options avaliable to me. I prefer the second option of fitting a 2k floor probe as I will also be running OpenHAB and will not only want to pull the data but of course use it to do other logic, I assume something along the lines of this product will be suitable… Cable probe NTC 2kOhm, floors probe

If you could please provide some basic wiring diagrams it will be of huge help planning out my system.

I’m based in Borehamwood, Hertfordshire :+1:t2:

Many thanks


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Hello Nikhil,

It certainly looks like you are putting plenty of planning into your project, I’m happy to help you to achieve your goals.

Full PDF - https://www.mdar.co.uk/dl/forum_assets/Underfloor_example_with_heating_interlocks.pdf

This is the most extreme method, but it will work very well and gives you precise control.

I’ve had version 2 of a solution running in an assisted living project for nearly ten years without any issues.

That probe should do the trick, if you want to arrange sending one to me, I’d be happy to hang in onto a VMB4AN and let you remotely access it for evaluation.


I could bring an entire demo rig to you, if you want to explore configuration options before committing to a purchase.

Borehamwood isn’t too far from me or we could meet at the London distributor’ place and you can see a working Velbus home.

Please let me know what works best for you.

Best wishes,


The thermistor inside that slab sensor is less than £1


I have been known to solder one or two onto long cables and heat shrink the ends…






Thanks a lot for all the info shared, this has confirmed a lot of things for me. Since the house will be completly gutted, although the more complex option 2, its by far the most flexible for what I’m looking to achieve (full Velbus lighting and heating control).

I’ve put a spreadsheet together of all the various Velbus components I require for what I’m trying to achieve, so over the coming couple of weeks as I finalise the requirements I will happily share this with you, 1, to confirm all is correct and 2, any more efficinet way to implement.

Once we have spoken though it would be great to meet and run though the solution and more complex use cases before purchasing as config of the system will be handled by myself when being commisioned. For config simply looking to implement Velserv as the TCP/IP interface and hook into OpenHAB, etc…

Many thanks


There are plenty more wiring plans like that, if you want them.

These might be of interest.
Shows Mains lighting as well as ELV DC (LED Strips in Single colour or RGB)

Heating with interlocks, so that valves can be moved daily without calling for heat.

Happy to review whatever you have created, I might be able to suggest alternative solutions.

Can I suggest you take a look at the (retail price) quote generator that the London distributor has on their website?



You can create as many projects as you wish, with as many rooms / zones as you need.

We find it is a great way for people to focus their minds on what each room / zone requires.

The quote will also include things like the total DIN space required and suggest a Future Automation cabinet to put it all in.

These can also be order as a Pre-Built unit, with all the Velbus hardware installed and pre-wired to a connection rail, with whichever combination of RCBO / AFDD etc you require.

Obviously you can deploy as many cabinets around you property as you wish, the tool is just a guide.

The SuperKlick tool will also add a mini computer, pre-loaded with the

If you send me or Superklick the PDF that the tool outputs, we can review it with you.

That sounds like a great idea.

I’m a big fan of asking questions at the start, it saves all the finger pointing at the end.

I assume you have read the tutorial documents for commissioning a Velbus system, or have watched plenty of videos.

I am going to assume you have previous experience with other technologies, so would encourage you to take some training, as there are tricks with Velbus that make it a much faster system to deploy.

You are welcome to remotely connect to a demo unit and have a ZOOM session with me, to ensure you have all the skills you need to get started.

You may be interested to know that anyone attending in-person training qualifies for an enhanced discount rate.

Do you have a donor computer in mind?

We supply pre-configured Odroid C4 machines to ALL UK customers as part of a base system.
(unless they have more powerful machines lined up to do the job, for example some larger customers prefer to use a full server, especially if they run systems like openRemote.io

I look forward to hearing for you.

Best wishes,

Hi Stuart,

This is actually exactly what I was after, an all-in-one solution along with the Future Automation cabinet that can be pre-configured off-site and hung up on the wall and all the lighting/heating circuits wired in.

I’ve read through all of the Velbus hardware and software setup guides, and pretty much all of the YouTube videos. I know which lighting and heating circuits I need to control, and have a fairly good understanding of all the various components and how they fit together. (just need some validation and cross-checking from the experts!)

I’m actually glad to see such a setup offered by Superklick where it provides a microcontroller and associated software to integrate with OpenHAB, etc, as I was simply going to use a Pi to host OpenHAB and VelServ. Bottom line I want it set up so that if the Pi goes down the only functionality I lose is convenience and I can still control the entire setup through any one of the Edge Lit panels, which from my understanding is pretty much the default.

I have created a Superklick project and filled in for all rooms inc lighting and heating circuits. Do you have an email address where I can share the quote directly with you as the PDF has PII data on it.

I have a question about the quoting tool as I would like to use the setup for controlling all of my 240v LED dimmable lighting circuits through a VMB4DC → FINDER SLAVE DIMMER 0-10V 230V 400 → 240v lighting circuit, as I understand this is the recommended Velbus config for this setup. Not sure if the Superklick quoting tool does not go into this detail for quoting/needs updating or if my misunderstanding, as it quoted me the VMBDMI-R for the 240v LED dimmable circuits.

Since controlling mains dimmable LED lights I want to use a compatible trailing edge dimmer and not leading (VMBDMI-R), hence wanting to use the VMB4DC → FINDER setup for maximum lighting compatibility.

Happy to discuss more over a call/email until we get to a final solution.

Many thanks


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That’s what we have been planning for a while.
What you are working with is Version 2

Version 3 will have a nice twist to it.

My only advice at this stage would be to suggest that you look at having your heating / cooling controls in a different cabinet, so that they can be mounted next to the heating manifolds etc AND be totally isolated from the mains when the heat source supply is switched off.

Meaning that a heating engineer can be confident that when they flip the breaker, EVERYTHING that they are likely to touch will be OFF.

Heating is easy enough, just as the SuperKlick tool creates.
One relay contact for every heating zone
and a spare for the Heat call

Lighting should be fairly straightforward too.

Happy to confirm / validate your choices

Exactly, that’s there to make it easy for everyone.

Some installer prefer to do their own thing, which is perfectly okay.
But most want a “catch all” solution.

Yes, that’s exactly how Velbus is designed to work.

I call it the “mission critical” method.

What you NEED to work, will.

Sure, send it over as a PM on here or direct to my email

That tool is designed as a “quick tool” for anyone to access and get a fairly accurate cost, with the view to then engaging in a conversation to go further.

So far, it has cut down on the “how much is it, oh, I can’t afford that” or the “I don’t know what I want” conversations.
What they (Superklick) have found is that the quantity of enquires has done down, BUT the quality has gone UP.

We / they are in the process of adding the Finder Slave dimmer option along with things like MODE lighting and ANYTRONICS dimmers.

For now, we review each project and evaluate if VMBDMI-R are the best option or “something else”

Over 3 dimmers and the Finder is the best option.
Over 12 dimmers and suddenly a MODE lighting multi channel dimmer pack becomes an option.

Cost per channel, it works out pretty much the same.
(That is, until March 2023, when ALL the prices from everywhere will be changing)

Indeed, the Finder Slave dimmers are the best option for flexibility, as they can be set on a per channel / circuit basis.

MODE lighting dimmer packs have to be purchased as an option per pack.

ALL Leading edge or ALL trailing edge etc


Mains replacement LEDs are the bane of everyone’s life.
If you have the option to install LED strip or PURE ELV LED light sources, I would strongly advise it.

Send over your PDF and let’s have a chat.


Hi Stuart,

Apologies for the slow reply, it’s been quite busy on my end!

This is something I was thinking of too and locating another cabinet in the utility/plant room. I am putting an overlay drawing on top of my floor plans which I will share with you which shows the lighting circuits, glass panel, and cabinet placement.

Sound great, I have quite busy days, but I am soon to be done with the diagram to help visually and I will the SuperKlick PDF over too.

This is interesting as I will be having more than 12 dimming circuits, I didn’t know the MODE multi-channel dimmer packs were compatible with the Velbus system, but we can discuss this in more detail.

Speak soon!

Many thanks


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Hello @nikhilk12

How are you getting on with this project?

Or have you already met Nitesh and are now living in a Velbus equipped paradise?