Zigbee / open thermostat controller without battery?

Hi everybody,

I am using Eurotronic and Moe's brand thermostat controllers for my radiators. They are connected via zigbee2mqtt.

However, I have two big issues with them:

  1. it seems like they (only sometimes) don’t work correctly any longer before the battery is “officially” low, so there is no way to predict when this will happen; a trigger warning if “battery remaining” is under x percent (if the device even reports this) or “battery low” is “true” does not work in this case

  2. they run on battery period

Are there any devices you can recommend from personal experience that are wired?

My current solution is/was outlet to 2xAA battery adapters; so I plug these adapters into my wall outlet and in the thermostat controllers, then they are always powered. But I’ve read that these devices are not as “good” as batteries themselves, because of something related to voltage or something like this (I don’t remember exactly and cannot seem to find this blog post at the moment).

But this seems to be true. I had to exchange one thermostat just now because it would no longer allow controlling HVAC mode. I could successfully change the temperature, but I could not turn on/off/auto. When I exchanged the thermostat, it would not even pair. After almost losing it, I used batteries to pair it instead of the outlet-to-2AA adapter, and bingo, they would pair right away.

So while I would be fine keeping these devices, but using the wall adapters, I don’t trust them any more. Normal batteries don’t provide a great experience due to 1) above. Sometimes they are low, yet the thermostat does not report this, and then I won’t know - until I randomly find out.
If I have to manually check my thermostats every so often, I might as well not have smart ones.

Is anybody here using wired / non-battery thermostats to control their individual radiators? If so, which brand / model, and would you recommend switching to them? Zigbee would be ideal, but if they ran on tasmota or ESPHome, I’d go for them as well :slight_smile:

Thanks in advance for your ideas

Thermal actuator?
They run on mains.

You need a separate temperature sensor and smart plug.
For us they work just fine even though they are only on/off, nothing in-between

I am talking about something like this.

These have an internal temperature sensor. If you set temperature to xyz degrees, they will determine whether the thermostat needs to open the valve, and, if so, how much / for how long.

MOES Heizkörperthermostat Smart,Heizungsthermostat WLAN(MOES ZigBee Hub erforderlich),Thermostat Heizung Programmierbarer mit Fenstererkennung, Energiesparend, Kompatibel mit Alexa und Google Home https://amzn.eu/d/9ASBAri

But why do you want an internal temperature sensor that is incorrect anyways?
You can’t possibly get a good reading when you have a temperature sensor on the heat source.

The thermal actuators can also be controlled using a generic thermostat and will work the same way as a TRV.

Thank you! I see. I was not aware of this type of device.

Is there a lot of on/off activity involved with these?

Let’s say my sensor is measuring 19° and I set the climate entity to 21°. I assume the actuator will then fully open the valve, correct? But then it will close it once 21 degrees have been reached (or if they have been reached for time x, depending on the automation).

But if there is only open/closed, I imagine the device constantly regulating, unless the automation prevents this. Let’s say the automation compares the sensor to the set temperature every 5 minutes… then the radiator will be either on or off for 4:59, then check again, then either be on or off for 4:59, then check again, etc. etc. - is this correct?

Unless I check every 30 seconds or so. This way, the time period would be great, but I could imagine this being annoying in the bed/living room etc., if the device constantly fully opens or closes 100%…?

These devices I use currently don’t do that. They are capable of regulating the valves anywhere between 0 and 100%. And you are absolutely right, the temperature measurement right at the radiator sucks!! But we have been using this for a long time and kinda got used to it. I mean, all the automations are working at the moment. Perhaps a radiator is set to 22 degrees, but the room is only at 18 where I am sitting. This is currently okay, because the automations are set up in a way that takes these “false readings” into consideration.

Either way! You got me curious, gonna order one right now :slight_smile:

No not really…

Since we have our radiators off when we leave home there are large dips.
But during the night between the 28 and 29th there is about 1.5-2 hours between the “on” periods.
The gap at 6 on the 30th was 3 hours.

I don’t think they regulate more than the TRVs we had before.

Yes the generic thermostat can be set to this behavior, you could also allow it to go slightly above set temperature.
It’s up to you.

I wouldn’t use an automation, use the generic thermostat.

I skipped a lot of your post above this since it talked about automation.
I really don’t recommend it.
Create a generic thermostat and then create an automation to set the thermostat.
Automations with heating is prone to fail.
But regarding what I quoted.
I assume you mean because of noise?
Thermal actuators are slow and are actuators. They move in and out, not spinning.
This means they move completely silent.
You only hear the sound from restricting the water, nothing at all from the actuator.
But they are slow. And I mean slow, like minutes slow. Ours probably take about 5-7 minutes to go on or off.

I agree, buy one to test with in one room. Preferably a room where you notice it so perhaps not a bedroom where you just are asleep in.
There are versions that can regulate it to a semi closed position but they are about 5 times more expensive.
So my recommendation is to test one and see how this works.
We bought one and got sold on the idea within a day.

Tack!

I wouldn’t use an automation, use the generic thermostat.

I set up a test generic thermostat. It looks good. But I still have automations controlling this (or rather, my actual) thermostats. So for example, at input_datetime.arbeitszimmer_heizung_00, set climate.group_arbeitszimmer to input_number.arbeitszimmer_heizung_00, same for (...)01, (...)02, etc.

Thermal actuators are slow and are actuators. They move in and out, not spinning.
This means they move completely silent.

Wow. That is already the selling point. So yeah, after reading your post, I ordered one, expecting it next weekend. After reading this, I ordered yet another, because it had faster shipping :smiley:

Thank you so much. If these devices I ordered (30x1.5 230V actuators) work as expected (so as the ones you use), I will switch each and every zigbee controller with one of these.

Well, I might research if there are semi-automatic ones that can both be controlled manually as well as via smart outlet. So in case of a power outage, the heat would not be completely on (NO) or off (NC). But yeah, first I’ll test those that I ordered this weekend :slight_smile: fun project.

If you use the NO version then they need power to make the water flow, OR you just unscrew the actuator and it will release the pressure on the pin.
But then again, will there be any heat in the house if the power is out?
I don’t think ours will work since I assume there is a pump making it flow in the condominium.

I’m fairly sure they will work fine.
I just bought a no name cheap version on Amazon.
Since these are so simple they don’t need to be a good brand version

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I totally forgot about that. This is the way! I have two of them in use now and already feel like they perform much better than the zigbee devices. While I am not too fond of the operation time, everything else is great.

Now to replace the old ones step by step with these actuators. Thank you so much for recommending them.

You mean they take a long time to open and close?

The thing I love about the actuators is they are more or less set and forget devices.
I have not once thought about the heating and if they work as they should, which was a constant issue with the TRVs we had.
Perhaps it was a shitty device, but sometimes they didn´t close or open as they should and you had to figure out why, or there was battery issues.
This setup really just works.