CliveS wrote:siclark wrote:My vote is (a).
Clive?
And my vote is B
I watched the Shelly Custom States this morning for 20 minutes and the Setpoint was 18c, the Rad Temp was 17.1c so the valve should be open but it sat on 0.
The Rad Temp went to 17.2c, 17.3c, 17.4c over a 20 minute period and still the valve position was 0, at that point I increased the Setpoint to 19c and the valve-position went to 49, I reset the Setpoint back to 18c and it stayed at 49 so it seems to me it should have updated when it was letting the radiator go from 17.1c to 17.4c but did not.
I would not trust the valve position to trigger the flame on and off, it also takes 2-3 minutes for a change to occur, hence why I trust B and not A
Joining the conversation, I would vote for A
It could be made auser selectable option.
I think the 17.2 -> 17.3 -> 17.4 could just be an ambient change, unless you checked the input flow?
I am currently have 12 TRVs and 6 H&T pluses being controlled by Node Red.
In my experience, dodgy valves can cause issues e.g. the TRV might say it is open 8% but still no water is flowing. Also when there is just a small difference between between the setpoint and the target temperature it can take a while to open up.
Another setting to set (which seems counter intuitive) is Settings > Under Floor Heating Mode. [Оnly the data from the external sensor is valid, without taking into calculations changes from the built-in one.]
On a couple of radiators with dodgy valves, when the TRV is turned off (valve = 0), I force a calibrate that makes sure the valve is actually closed.