I’ll keep that in mind. Ideally I would like to find a device controlled by a solenoid rather than a motor, that would probably be more efficient for my intended usage.
Thermal actuators are wired to 12/24/110/240 volt and is completely silent.
If you need gradient control then you must choose one that handles PWM, most are just on/off.
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I would say that is not an issue for me.
Here is January of this year, the thermostat is set to maintain between 21 and 21.5.
The red line indicates when we were home, when we are not home the heating is turned off.
Our heating is controlled by thermal actuators and only have closed or full. Nothing in between.
And during this weekend when someone was home the whole time it overshot the temperature with 0.1 degrees Celsius for one hour.
Overshooting will probably depend on many factors. Personally I prefer small changes in valve opening percentage, they will keep the noise short and save battery power.
Thermal actuators are completely silent and run on mains.
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In that case I’ve not yet seen any thermal actuators in my life. I just know that battery powered TRVs are called thermal acutators as well.
can you send a link to somewhere you can buy one
You can buy them anywhere.
Amazon, aliexpress, probably wish, or perhaps also your local plumber.
Keep in mind there are a lot of versions of these.
First the voltage.
Then there is NO or NC. Pick your poison here. Either they need to be powered to give heat or they need power to shut off the heat. I picked closed version. Meaning in case a power out we won’t get any heat, but we can always unscrew the actuator to get heat.
The last version/option is to get a PWM controlled version. These are a bit more expensive.
Also keep in mind there is nothing smart in these. You need to control them with a smart plug or similar and have some way of sensing the room temperature.
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Thanks yes all absolutely clear, I already placed an order on Amazon before your reply for a random one, NC 230V, I have a bunch of these sitting around to control it so I’m all set, I’ll let you know how it goes thanks again!
the SONOFF TRV is probably a good option, which works seamlessly with Zigbee2mqtt.
Hi @arnoldxt,
It’s quite a long time since you asked this but thought I’d share how I have done it.
My boiler is quite old and I have one of those external timer panels where you can set times for Hot Water / CH and then also override it. It also has an external connection to an old-fashioned room thermostat in the hall.
Part of the reason I started this project is that I rarely care what the temperature is in the hall, and care more about the rooms I’m in for long periods.
To control the boiler, I have just disconnected the room thermostat and replaced it with an ESP32 running esphome, with a relay attached to one of the pins. This presents a simple switch in Home Assistant which can now be used to turn the boiler central heating function on or off.
EDIT: Actually it’s not just a relay hanging off a pin, I got a board with ESP32 and 2 relays combined, like this: ESP32 Relay x2 | devices.esphome.io
I just leave the old timer set at heating always on, and control it all from within Home Assistant, including the timer function just with a scheduler.
Hope this is of use to someone.
Cheers,
Dunc
I know this is a bit old now but how are peoples set ups? still working? Any issues with age. (Valve blocking, actuator failing)
Are they loud i want some in bedrooms?
In my opinion TRVs are loud, that is why I switched to thermal actuators
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I’ve just ordered my first Sonoff Zigbee TRV to see how well they work. I have previously tried the Shellly WiFI one quickly decided it did not work well.
Whick ones?
What battery you planning of using? I would probably want to use rechargeable.
Can you let my know how noise they are?
They all work pretty much the same. You give them power to turn on the radiator (NC) or to keep them closed (NO).
You need to pick one version, I have NC version since you can always unscrew the actuator to get heat.
Just search for them on amazon or somewhere, they work on mains or 24 volt usually.
The sonoff TRV is remarkably quiet and affordable but only knows on/off sadly. I can compare it with an Eurotronic Spirit Zigbee TRV which is louder and seems to have worse battery life so far and has been more finicky in combination with zigbee2mqtt but it does set its valve to values in between completely open and closed. It is also more expensive and older. I bought my eurotronic spirit zigbee TRV valves used, so it’s not necessarily a fair comparison.
I think the simple Sonoff TRV is a good fit for some rooms which don’t have to be heated all the time. Also keep in mind that radiator valves by themselves will make some noise when they are half closed because they resist the water flow. Depending on your pumps this might be enough of a slowdown that it becomes audible. But of course this also applies to dumb manual thermostats, so you can check this beforehand.
So: if there is a lot of thermal mass in the room or it is infrequently used, a on/off TRV like the sonoff might overall be less annoying.
I am just getting started replacing my manual TRVs with smart ones again for this season. Maybe I can share more field reports in a few weeks or so 
On a side note: there are lithium rechargeable AA and AAA batteries which have a voltage similar to non rechargeable ones so if your TRV keeps reporting low battery due to the generally lower voltage of NiMh cells, you might want to give those a try
Aside from the hardware, what is a good way to integrate non-binary TRVs in Homeassistant? It seems to me that HA is geared towards ON/OFF kind of heating. The thermostat entity and the history charts it produces suggest that. I would like to see the heating demand or valve position in % in my charts, not just ON/OFF