It would be very useful if the SONOFF TRVZB Gen2 could report its actual valve position (0–100%) via Zigbee.
Many other manufacturers already provide this functionality, and valve position reporting has become a common and expected feature in modern Zigbee thermostatic radiator valves (TRVs).
Exposing the actual valve position would allow better integration with smart home systems such as Home Assistant, ioBroker, and Zigbee2MQTT.
It would enable more advanced heating automation, improved monitoring, and better heating efficiency, especially when using external temperature sensors or custom heating controllers.
Since this functionality is already widely available in competing products, it would be a valuable addition to the SONOFF TRVZB Gen2.
Ideally, the valve position should be exposed as a read-only Zigbee attribute that updates whenever the position changes.
It is, but not widely. I am not convinced that valve position reporting is currently a common or expected feature across Zigbee TRVs. Some devices provide it, but many popular models do not expose it via Zigbee.
I am also sceptical about the claim that this feature would significantly improve heating efficiency. In most installations, heating control is primarily concerned with room temperature, target temperature and how the room temperature changes over time. These are the parameters that tell us whether the heating system is achieving its goal.
Valve position alone tells us very little about the actual heat output. A valve opening of 50% does not necessarily mean 50% heating capacity. The result depends on factors such as flow temperature, water flow, radiator characteristics and the hydraulic balance of the heating system. Without this additional information, valve position is a rather limited control signal.
It could be useful in advanced control strategies, but simply exposing a 0–100% value does not automatically make the control loop better or more efficient. In many cases, it would be a diagnostic metric rather than something that directly improves heating performance.
Realistically, I suspect that most users would rarely use this information beyond looking at it out of curiosity or checking it when troubleshooting a problem.
I have nothing against adding this feature. If the hardware and firmware support it, exposing the valve position as a read-only Zigbee attribute would be a welcome addition for those who need it. I just think its practical benefits for heating control and energy efficiency are being much overstated.
Yes. Knowing the state of the valve isnt a way how to improve heatingefficiancy, but it is good to understand whats going on in your heatingsystem currently.
I noticed some times, that the smart mode acted not like expected. For example a 2°C temperature difference and the valve movement was just hearable a microsecond. It felt almost like its opening just 5 or 10%. Then the temperature was never reached.
Later this evening i had an overshoot for around 1.5°C and the radiator was still “to hot”.
But since they announced the smartmode and the new TRV, i was expecting a better heatingperformance since the “smart” mode should know when to open or close the valve.
If the temperature is for an hour 0.5°C below target, it should slowly increase the valve opening percantage step by step. Same with overshoot. When the current temperature reaches the targettemperature, the valve should decrease the opening step by step until room and radiator are in an equilibrium state where heatingperformance compensate just the room looses.
This is kind of how an “classic” TRV work but just mechanical.
Before you can start investigating deeper for the PID controller, you have to know how the valve behaves. This is slightly not possible without this exposure.
Ive testet around 5 different zigbee TRVs and all of them exposed the current position.