I am writing to request a review of the logic applied to the Minimum Valve Position (Closed) and Maximum Valve Position (Open) settings for the Sonoff TRVZB Thermostatic Radiator Valve.
Currently, the system enforces a non-intuitive restriction:
{Minimum Valve Position (%) + Maximum Valve Position (\%)} > 100$$
This restriction, combined with the logical requirement that Maximum must be greater than Minimum, severely limits two critical and common use cases for a TRV:
1. Hydraulic Balancing (Limiting Maximum Flow)
The goal of hydraulic balancing is to limit the maximum heat output of an oversized radiator (e.g., in a small room) to ensure the other, smaller radiators in the house get enough hot water.
Desired Setting: We want to set the Maximum Valve Position to a specific low value, like 70%, and the Minimum Valve Position to a standard 0% (fully closed when idle).
The Problem: The current restriction makes this impossible, as 0% + 70% = 70%, which is not > 100%. The user is forced to increase the Minimum Valve Position to 31% or more just to be able to set the Maximum to 70%.
Consequence: The radiator is never fully closed and continuously adds unwanted heat, defeating the purpose of a smart thermostat and wasting energy.
2. True Full Closure
To save energy, users must be able to set the valve to truly close when the target temperature is reached or exceeded.
Desired Setting:Minimum Valve Position (Closed) at 0%.
The Problem: Due to the sum > 100% rule, setting the Minimum to 0% forces the user to set the Maximum to 101% or more (which is not possible), or the system rejects the setting. This unnecessary constraint prevents using the full 0% to 100% range freely.
Proposal
Please consider removing the restriction that the sum of the minimum and maximum percentages must be greater than 100%.
The only necessary restriction should be the logical one:
Maximum Valve Position (%)>Minimum Valve Position (%)
Allowing users to set Min = 0% and Max = 70% (or any other valid combination) would greatly improve the utility, energy efficiency, and overall user experience of the TRVZB for advanced temperature control and hydraulic balancing.
I don’t know what kind of bridge are you using but if I take as an example my Zbbridge-u and looking at TRVZB setting “valve opening percentage” it’s a bit tricky but obvious that the sum of open and closed percentages must be over 100%. That’s because 0% setting for “valve opening” would force the valve to be closed (sonoff seems to complicate things here).
I made a picture as an example and I know it’s not easy to understand. The two vertical blue lines in the “valve opening” raw and in the “valve closing raw” represents a setting of both to 30%. That would be an absurd situation because “valve opening” to 30% means that the real valve is more closed than “valve closing” to 30%.
Both settings at 50% would mean no movement, real valve always midway. That is why setting sum must be over 100%. This is my thinking!
Ciao, posso chiederti di verificare se dopo l’aggiornamento a 1.4.0 l’app ti fa salvare come percentuale di apertura 100 e chiusura 100? A me esce un messaggio di errore
Credo quindi che questo sia un bug da segnalare allo staff di EweLink.
Hello, I think the logical part that wants the opening value to be higher than the closing value is an error in the evaluation of the entire scale of possible variables by EweLink. I tried to set “closure” to 100% and “open” to 50% on a TRVZB upgraded to V1.4.0 as you asked me and I have the same logic error as you. I haven’t updated all the valves yet so I tried the same operation on a previous version, the V1.3.0, and you know what? I had the exact same problem, with the same restrictive logic. I deduce from this that the problem is not the thermovalve but a wrong restriction inserted by the EweLink team in their APP (perhaps in the latest version? I don’t know if it worked before, did you use these settings without any problems before?) Is it probably not clear to them how the valve opening and closing rates work as Sonoff intended? Using this new restrictive logic it would no longer be possible to set the default opening=100% and closing=100% values because even in this case the opening value is no greater than the closing value (but this is a unique case).
The new logic would work correctly for closure values equal to or less than 50% because from there down it is obvious that the opening must be at least 51% (therefore greater than the closure) to have a minimum movement of the valve.
For closure values above 50%, part of the logic should be on the contrary, with opening values below the closing values.
Example 1:
Closing 51% Opening 50%
Example 2:
Closing 91% Opening 10%
Example 3:
Closure 100% Opening 1%
Correct logic:
Closure + Opening > 100%
Opening > Closure WRONG
Opening < Closure CORRECT
So I think this is a bug to report to the EweLink staff.
I just installed a couple of TRV valve from Sonoff and find this incredibly frustrating. I was hoping to be able the limit the valve opening but this restriction makes it impossible. On top, I immediately updated the firmware of the valve to v1.4 and now cant even select 100% opening/close so on top the valve is not truly closed.
Please give this some priority, I don’t want to be forced to used the valve at full blast or full closure every time.
In my particular case I want to set a valve to open to ~40% (small room, heats very easy), which is impossible with the current conditions imposed by the app (impossible to make open + close > 100 if open = 40 and open > close ).
On top, I want to use this thread to get some explanation on how these opening/close % are meant to be used.
I understand “% open” is relative to the closed position and “% closed” is relative to the open position. What is not clear to me, how do these % interact which each other? Are they also relative to fully open/closed valves? Or relative to the % used?
Example:
% open set to 50% (valve allowed to open until 50% from fully closed)
then for closing:
Option A: % closed set to 50% (valve allowed to close from 50% to fully closed taking as reference the fully open position)
Option B: % closed set to 100% (valve allowed to close from 50% to fully closed taking as reference the % open at 50 setting)
Option B would mean that % opening takes precedence over % closing, but it could perfectly be the other way around. Is there somebody that could explain this setting to me? As @s.minguijon pointed out, I want to limit the amount of flow on my radiators based on individual room conditions
I’m having the same issue as @s.minguijon and I agree with your interpretation. What I still don’t get, is how do you then limit the valve opening till a % given the limitations imposed by the app? Lets say you want it to open only until 30%? or until 60?
Hey, I’m having same issue. As i understand a fix or solution is on the way. Just it got me thinking, that being able to set different levels or presets of valve opening, like 1st level 10% opening, 2nd level 20% opening of valve and so on could give some good opportunities for scene creation, like turning to level 1 or 2 over night to save on heating or just incremental heating of the room instead of blasting fully opened valve until room temp reaches desired temp.
At the moment both open at 30% or 60% are not possible supposing you then want to set closing at 100%. That’s because you would be in the “bug” case where closing % must be greater than opening % and EweLink app won’t let you do that. You have to wait for the fix that should be released in some days.
Which firmware version are you on? supposedly v1.4.2 will address this which should be already released. It still doesn’t show up for me to update so I can’t test it myself….
