Do anyone know of a TRV where it is possible to set the valve opening instead of the temperature.
I have TADO as of now, of course not possible, However, also based on their rate limiting, I look into replacing all 18 TRV’s.
As part of this Im looking into TRV’s and the control. I have tried a cheap CN (MOES) and it works well over Zigbee, however the control is as bad as TADO. I was reading from someone that the Danfoss Ally could be controlled on opening percentage, however this is not working, only temperature. Much better control in the Danfoss, however still not valve.
You might ask, why control the valve opening. The aim is to ensure the return temperature from the radiator is below 35 degrees. This, as my community heating is “giving me a fine for high return water temperature”. It actually works super well with the TADO, I just switch them off when high return temperature, however not really smooth, as the TADO is opening full for a few minutes, then shut down for 10 min and then open again.
I believe I can do much better with a simple HA automation, if just I can control the opening.
Any ideas? Does not have to be zigbee, however would perfere.
I think many look for TRVs that can take a direct valve control command, but they seem to be scarce in supply.
I have a Homematic IP setup and I can see the valve opening, but not control it directly.
Homematic IP TRVs however do not open up fully, but adjust it to the difference between current and target temperature.
This means I can have an automation that set the target temperature, but with a max difference between current and target temperature. I just trigger it on state changes in the current temperature, so it keeps the value updated at all times.
I have a Danfoss ally variant, and similarly, you can read the opening but not control it. You can cheat it by making it regulate an external temperature sensor, which in practice is just a value that you send to it over ZigBee. It doesn’t have to be the temperature in the room
So if you want you can figure out some combination of return temperature and room temperature as the current temp, together with a setpoint, and have an automation send that to the TRV.
I think there are semi-dumb actuators with a plug that you can set directly. In another thread on TRVs someone was very happy with those.
Using Valve opening degree and Valve closing degree you can effectively open the valve to the desired opening %. E.g. setting opening degree to 30% together with closing degree to 70% effectively opens the valve to 30% (both need to be set at the same time).
For example Versatile thermostat integration uses this feature to proportionally control these Sonoff TRVs. I have 6 of them installed in my home, works just fine.
Hi Martin,
Just received a test Sonoff TRV and I have it running, it works. The opening/closing degree is there, and looks like it is working. I believe the “opening degree” would solve my problem, as this is a “max open degree” as I understand the description. Just need to figure out the right “max degree” for each radiator.
This leads me to my question. Do you know if there is a “current opening degree”. I can not find anything I can convert/use .Maybe “idel steps” and “closing steps” is related to this?
I do not think you can get the “current opening degree”. The way the valve is designed is it is either open (to the maximum value of Opening Degree) or closed (to the Closing Degree where 100% = fully closed). The internal thermostat control will automatically (fully) open or (fully) close (within those limits) based on the target temperature and the setpoint.
If you do not like the on/off control, you can work around that by using something like Versatile thermostat integration (or even your own controller implementation, e.g. PID). Then you can proportionally control the valve from 0 to 100% by what I tried to explain before: setting opening degree to 30% together with closing degree to 70% effectively opens the valve to 30% (both need to be set at the same time). This way you practically prevent the internal on/off control from working because the valve is both open to the maximum opening degree and closed to the maximum closing degree
