Cost effective offline radiator control

This is an international forum and choices vary. In which part of the world are you living?

Hi, I’m in the UK - England to be more specific. :slight_smile:

I am in the US where radiators are not too common.
I know our Zigbee & Z-Wave developer is in the UK though. Perhaps @chris has some suggestions.

Unfortunately the “what hardware should I look at” is one of those personal choice questions, so my view is that ZWave is possibly a good choice, or ZigBee - both are reasonably similar, and many manufacturers do provide similar products for both systems. In the UK, ZWave is probably more available than ZigBee, although there are EuroTronics radiator valves available for both systems.

I don’t tend to use radiator valves though and from what I’ve seen from others, the current solutions aren’t necessarily the best (eg the EuroTronics Spirit valve). These suffer a little from using internal sensors which don’t work so well with the thermostat being so close to the radiator. In theory they can be controlled externally, and some people are doing this, but it is implemented in a non-standard way. I think it’s also possible to use external sensors, but I’m not really familiar with this.

I’m sure there are similar valves that work with other systems - a good UK supplier is Vesternet so you can surf around there to see if there’s something that takes your fancy and then check back to see what is supported here…

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Hi Steve

Welcome to our happy band.

Are you looking for a wireless system or a wired one?

There are lots of threads on these subjects, I’m happy to point you in the direction of some of these to give you something to read.

Good luck


(Also in the UK)

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For reference I’ve got the Hive TRVs and I know they use zigbee. The standard Hive system requires an internet connection but it may be possible to roll your own solution if you don’t use their hub.

Hi, Thanks for the question - it is a good one. I don’t really know. I’d expected to go wireless (because that seems to be what the proprietary systems are promoting) but I’m not opposed to a wired solution in principle. One thing that concerns me about the wireless TRVs is that they must be battery operated… and I expect to always be cursing flat batteries.

I’ve found these ‘wired’ units…

Might they work on ‘ordinary’ radiators? I assume I’d need (lots) more kit to inegrate them with OpenHAB?

I’m really hoping that someone will give me an anecdotal: “I wanted that - I’ve done it… it’s simple; it works; the parts were fairly cheap… I bought X and Y - and it took me Z hours to put it all together.”

I’ve been struggling mainly because I can’t see ‘just what I want’ - the most difficult bit seems to be valve actuators that integrate with an open-source home-automation system. I can see lots of adverts - but none that seem to be associated with a crowd-sourced “Great solution, good value for money” appraisal.

I’m prepared to hack hardware… and I’m prepared to pay fair prices for hardware that works nicely in an open-source solution. I’m trying to get a leg-up on how best to get a reliable solution.


Fibaro makes z-wave radiator valves - . I have no experience with these but I’m running bunch of fibaro rollershutter controllers and switches and they are really solid - great build quality and features. They are not cheap though.

The Fibaro “The Heat Controller” units look really nice, and come with an external temperature sensor (from memory). I just wish they would bring out an Australian frequency version :frowning: As linked above, there are a range of smart thermostatic valves around.
More broadly, the z-wave binding and kit from various suppliers (I tend to use aoetec) are fairly simple to use within OpenHab, and within the constraints of the z-wave protocol, pretty stable. @chris has done a fabulous job in making this available for us all.


Yes, screw-on actuator heads for push-pin valve bodies are pretty standardised.

The pain is in running the wiring of course. I would where possible run individually back to a central control point, likely where you’ve already got pump and 3-port valve etc.

Well, functionally you’d just need on-off relays. You might wire actuators together to be operated as mini-zones (e.g. two rads in a large room, or as whole floors) for reduced relay count.
I would try for individual relays though, unless penny pinching, for flexibility. You can still do zoning in the control rules.

The task then is to select relays controllable from openHAB, that can be as DIY as you wish. Wireless tech like zwave provides relay units, eBay has 8-way ethernet relay PCBs, everything in between.

Disaster planning - what happens openHAB catches fire in midwinter? A manual override would be nice - you might choose a relay option with manual button, like a Sonoff. Or you might rely instead on the “final sanction” - unpowered actuators are generally ‘closed’, while if you remove the actuator heads from the valve, it is generally sprung ‘open’.

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Other than the obvious sales pitch, I don’t think there’s much I can say that will add to what @rossko57 has said.

This is just one example of the numerous threads on here about this subject.

Recommendable wired heating control system

Heating, controlling zones and timing are very common discussion points, which branch off into Wired or a Wireless based solutions.

It really boils down to three primary questions before you can go much further.

(Extra to what you have said already)

  1. Just how much :moneybag: budget do you have ?

  2. Just how much :clock1: budget do you have ?

  3. Do you want a fully wired, fully wireless or mixture for the basis of your solution ?

For my opinion, I would suggest you look at a solution that takes care of the Setpoint Vs Current Temperature logic, with openHAB2 being able to inject new setpoints as your scheduling requires.

As a wise man said…

“Let openHAB2 control the thermostat/s, not BE the thermostat”

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I’d challenge the word “want” here. Personally, I would probably “want” a wired solution if there were no other constraints - but practicalities always come into the trade and you often end up “needing” wireless since you don’t want to cut holes in your wall or you can only get certain sensors as a wireless node.

Given that sooner or later you will probably need/want to add wireless as you forgot to run a cable when you had the chance, you should consider that a fully wireless system will work a lot better than a wired system with a couple of wireless sensors added later. This is because most (good) wireless systems will use some sort of mesh network to improve distance and reliability, and the mesh network benefits hugely from a larger size (within reason - like any network - wired or not) and more mains powered nodes.

When I wired my house a few years ago when we put an extension on, I wired in a lot of Cat-6, and cabled everywhere I thought I’d need it, but still went with a wireless system as I still want sensors that ultimately are wireless.

As @MDAR states - this is just one of those questions which will be debated forever. Everyone has an opinion, and everyones opinion is valid as there are so many variables in this game - ultimately you need to choose what works for you.


I think that’s the optimal solution, but as you say, unless you’re particularly lucky / prepared, there’ll always be a need for a wireless solution somewhere.

I’ll be the first to admit that I’ve put in a TP-Link socket to get over a hurdle.

And again, you say it well here - - -

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That sounds like a great bit of advice. I’ll definitely alter my focus, now, from looking at TRVs to looking for controllable relays. With the TRVs costing between £50 and £100 each, and only being one component of the build, where I didn’t want to use the thermostat bit, it felt as if it could be an expensive wrong-step.

I haven’t excatly set a budget… I’m sure I can afford to do it - but I’m a awful skinflint. I don’t want to spend any proper money unless I’m getting a quality implementation of exactly what I want… and, even then, I’d like to do it as cheaply as is practical. I’ve rejected all the proprietary systems because they make me reliant on an internet connection. I don’t really want to publish when no-one is home to the internet.

As for time budget… Erm - unsure about that, too. I’d happily tinker for 50, 100 hours - perhaps more - if tinkering is what solves this for me. I’m really unsure when I’d fit it into my schedule - but… if this takes months (or years) that’s not necessarily a problem. I am living with what I have got - I just want to make it better - if I can.

I like the sound of that strategy. It makes sense to me. So - assuming I go for the ~240V AC actuators… What specific devices would provide me the relay/thermostat capability that I can drive with OpenHAB? Would I be forced to build my own? If so, from where would it be best to start the design? If off-the-shelf would work… can you suggest a product?



Would you like to take a guess what it might be???

Don’t forget most power valve actuators are supplied as heads only, needing a pin-operated valve to complete. You’d need to cost those as well - they are available without the TRV heads to be thrown away.

The plastic cap protects the pin and gives you a crude on-off function without any head fitted.

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Good thread here

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I’ve not forgotten them - I have them already… at the moment they’re operated by (very) dumb thermostats. I’d like to replace the dumb bit with a smart actuator… and then use separate sensors for temperature in each room to decide if I want the boiler on - and to control (programatically) which radiators I want to be the hottest. I want temperatures through the house on one control panel and to be able to use one of my set programmes - or adjust each room’s target (or scheduled target) centrally… while also being able to track how well my heating system is doing at chasing that target.

Sounds like you need…

And if you could get all that off the shelf for less than £145 + vat per room, that would be fabulous. (Plus cabling)

@ Everyone else… Can I say it yet… Please ???

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Hey maybe Velbus is something for you. Ask @MDAR for more information.

I for my part will use
Here is the manual

  1. it has virtual Thermostats where you can use external Roomtempratures from Openhab
  2. with virtual thermostats if Openhab dies and the station gets no new temperatures for the Room it changes to emergency operation.
  3. you can change the setpoint at the thermostat and in Openhab
  4. Pump connection
  5. Boiler connection
  6. OEM of Homatic ip

Greetings Markus

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