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
i dont really understand why you should send opening of 30% and then a closing of 70%
also i heared its better to to all with the set opening as otherwise it will drift more. is this right infomation or do you all set opening and closing?
(in my setup opening 0 is clsoing it completely)
i have also the feeling that with 20% the heating is still zero. maybe the pin needs more press to activate art least a bit of heating. is it right that opening_threshold to 20 would mean it would only start calculating with 20% still beeing 0 heating?
but isnt max_closing_degree exactlly the same value? so whats the difference?
thanky ou all for help
I think the first question is, what problem are you solving?
If you use the valve to control temperature in a room, and do not have other demands, it easy, just set the desired temp in HA or on the TRV. The TRV will open and close as expected.
my question was more:
do we need also closing degree in Sonoff TRZVB and why.
As you see in the image i only have opening degree set.
Ai told me that Sonoff TRVZBs can have problems when closing degree is also set and it is enough to set opening degree as this can fully steer the trv.
So i dont see why we need closing degree and if this would change anything.
But also i have the feeling the valve control is not really working so well:
i dont get any heat for values beneath 45% valve opening - ok this could just be my heating.
But also i have the feeling with similliar % degrees sometimes i get heating sometimes not - and then when i fully open to 100% and close again to the exact same value this always gets me heating. So it feels like the % is not the real valve % sometimes?
The blueprint you use, I do not know what it does, and still not sure about what you are solving.
I can confirm that both opening and closing degree is working. I can also confirm that it will “drift” a little over time, hence a static number might not help you. Has to do with your usecase.
I do not use closing_degree. I have them on 100% all the time. The valve will open, to the full opening_degree, when heating is needed and close when not. All my TRV’s have a different “percentage” where the radiator actually starts to heat. This is due to the mechanics of the setup.
All the TRV’s will not be the same physical distance from the valve, hence different percentages needed to generate heat.
Further, the “forward temperature of water” from the system might change when you feel it heats. If the forward temperature is 55, then you might need more opening before you can feel it, vs 70. My system, community heating, the forward temperature changes from day to day, controlled by the provider.
That was a lot of information, hope it make sense. If you explain you use-case, we might be better to advice.
I recommend reading the Opening / Closing Degree documentation carefully (e.g. here).
My understanding:
If you were to set the opening degree to 30% and leave the closing degree to 100%, the valve internal on/off control would still operate and regulate the valve only between these thresholds (will not physically open to more than 30%, but will fully close). The movement range in this case is 70% of the full range.
When you set the opening degree to 30% and the closing degree to 70% you allow the valve to only operate within a 0% range. This basically overrides /disables the internal on/off control and you keep the valve open to that desired position (30% in this case).
