Which wifi radiator valves?

I suggest you use smart thermostat products.
You can also use valves used in underfloor heating and connect them to some OH-controlled switch but then you have to take care of controlling the whole logic as well and you will also need temp sensors in every room.
Do not undererstimate the effort. My heating rules are 1k lines of code, just as a warning.

Oh, and you probably will not want Wi-Fi because usually there is no mains power available on radiators so you have to run on batteries, and Wi-Fi will be draining those fast.

Thanks for the reply,

I have temperature and humidity sensors in every room.

yes the wifi consumes too much, maybe in bluetooth, what would you recommend as hardware to interface to openhab?
because i saw netatmo but i understand that you can’t control the valves from openhab

I totally support Markus opinion to avoid WiFi in battery powered devices. WiFi is a really energy hungry technology, not suitable for devices that are powered by batteries.
As for your questeion about bluetooth: In my understanding buetooth is a near-field technology. It might be possible to use when you have a bluetooth controller/sender in every room. If you want to control thermostats deployed over several rooms, other radio technologies are better suited.

I suggest to look for radio controlled thermostats that are available in your country and then decide which technology suits your usecase best.

In my case I decided to use Z-WAVE for different actors/sensors. My thermostats are “Eurotronic Spirit Z-Wave Plus”. The usual disadvantage for batterie driven devices in Z-Wave (they need to “wake up” to receive commands, which can take a few minutes) is eliminated by the FLiRS technology (Frequently Listening Receiver Slave). These thermostats react nearly instantly to commands. I am very satisfied with their performance and a set of batteries lasts around 1.5 years in my setup. You would need a Z-Wave controller to connect them to OH. I do not know if these thermostats are available with alternative radio technology.

There’s a ZigBee version, too.

Try the Tado system and in particular their radiator valves…


Shelly have a wifi trv planned before Xmas. It will be battery powered but rechargeable.

There is also this

Although old it seems to be a smart solution to the battery problem

thanks to all of the advice, in the end I bought spirit zigbee, I configured them on openhab with deCONN, they work, now I need to make a good rule to manage each room separately


I would like to use an external temperature but I read that offset is used but I don’t understand how to do it.
can you help me?


To be honest, I don’t think I can help with that, sorry. The user guide gives no information how the thermostat needs to be configured to use an external temperature. The only hint for a possibility to do so is given in the description of parameter 8 by setting the parameter to 128. But: to be able to use another Z-Wave device as a data source you would need to associate the thermostat with a temperature measuring device. But the thermostat has only one association group, which needs to be configured to use the controller, the user guide is clear about that. So no chance to use another Z-Wave device as an external temperature data source as far as I see it.
My suspicion is, that the vendor planned to enable the thermostat to use a detachable, but directly connected thermometer without offering this option to the public (yet?).

Maybe someone else here has better information or can correct me in my assumptions.

You should not use an outside sensor. You want to regulate the temperature inside the house, so just let the inside room sensor do that. Obviously the colder that it gets outside, the greater is the heat demand, and the room sensor control loop will consequently open the radiator valve more to satisfy the demand.

ok I give up on the outside temperature.

I tried to play with the temperature offset, but sometimes the value of the temperature measured by the valve changes, other times it doesn’t. do you have any idea how it works?


I would imagine that the offset is a one time calibration setting, and should not be used as part of the control algorithm.

I agree to that, It is the best way to regulate the heating. It takes even care of sunshine onto windows which will reduce the need to heat via the radiator.

do I update offset every 30 minutes, too often?

I may be wrong, but I think offset is a parameter to compensate for potential calibration errors of the sensor; so it would be done one time only for the lifetime of that sensor…

I’ll explain what I want to do.
in every room I have a temperature sensor.

since the temperature of the valves is imprecise because it is too close to the radiator, through offset I try to compensate the temperature of the valves.

through this rule

rule "set offset temperature spirit zigbee trv"
    Time cron "0 */30 * ? * *" 
//	if(FF_Boiler_Control_Temperature.state!=OFF){
		Thermostat_Cucina_Offset.sendCommand ((FF_Kitchen_Temperature.state as Number).intValue - (Thermostat_Cucina_Temperature.state as Number).intValue + (Thermostat_Cucina_Offset.state as Number).intValue )
		logWarn("mylog","trv 1")
		Thermostat_SoggiornoG_Offset.sendCommand ((FF_FamilyRoom_Temperature.state as Number).intValue - (Thermostat_SoggiornoG_Temperature.state as Number).intValue +(Thermostat_SoggiornoG_Offset.state as Number).intValue )
		logWarn("mylog","trv 2")
		Thermostat_Studio_Offset.sendCommand ((FF_Studio_Temperature.state as Number).intValue - (Thermostat_Studio_Temperature.state as Number).intValue + (Thermostat_Studio_Offset.state as Number).intValue )
		logWarn("mylog","trv 3")
		Thermostat_Bagno_Offset.sendCommand ((FF_Bathroom_Temperature.state as Number).intValue - (Thermostat_Bagno_Temperature.state as Number).intValue + (Thermostat_Bagno_Offset.state as Number).intValue )
		logWarn("mylog","trv 4")
//	}
type or paste code here

There should be no need to constantly adjust the settings of a thermostat. It is the task of a themostat to regulate the temperature itself, according to a given setting. The only changes needed (in case you want to save energy and thus costs) are adjustments of the setpoint e.g. to lower the temperature during the night or when nobody is present.

I am with AndrewFG in that an offset is a static thing, a) for calibration issues and b) for comfort reasons: usually the radiator needs to be a bit warmer than the temperature at the place where you sit/work. Imagine you want to have 22 degrees Celsius where you sit and you know that the thermostat needs to be set at 24 degrees to achieve that. Now you know there is a difference of 2 degrees and you can set the offset accordingly. From now on you don’t have to calculate the setpoint every time for yourself rather than telling the thermostat " I want 22 degrees" (the setpoint in relation to your desk) and the thermostat “knows” it has to go for 24 degrees.

yes the reasoning is correct, but I have seen that the valve temperature is not constant but it needs to adjust the offset every certain time.
but maybe I’m doing something wrong

IMHO if the TRV is measuring a temperature that is not actually representative of the real room temperature, then it is simply not a good product.

Personally I use TRVs from Tado, and these work just fine. I would also expect that units from “big name” suppliers like Honeywell or Siemens should be fine too.

I have an old single pipe system, the valve is positioned at the bottom of the radiator, which is why it measures differently.
anyway I changed the system, I gave up the offset and I go to change the target every 15 minutes and for the moment it works, I am checking how long the battery will last