Make the auto start/stop hysteresis manageable

[MichaelVetter1979]

If I have understood the source code for the auto start / stop feature correctly, it works with a fixed hysteresis of 0.5 °K. Would it be possible to set this value individually using the configuration tool?

[jmcollin78]

Hello, in my understanding, all internal temperature are in °C and are formatted as °K only on the front. So the hysteris of 0.5 is in °C.

I may be wrong but that is my understanding due to °K issues.

[MichaelVetter1979]

Since hysteresis should describe a temperature difference it doesn't make a difference ( +- 1 °C is the same as +-1 °K). What I was looking for is the possibility to set a different hysteresis. I was hoping, it could be included in the configuration dialog insteat of using a fixed value.

[jmcollin78]

Hello, I will not make this technical hysteris parametrable because of the complexity it will add in configuration vs the enhancement.
Why do you need to change this ? What is your use case ? What issue do you try to solve ?

[MichaelVetter1979]

Hi,
I'm using vtherm in our main room to optimize the heating cycles of our AC heat pump. In the same room I use two radiators with some zigbee thermostats. These only activate with a hysteresis off 4°C, which is much to high. Therefore I use Better Thermostat for these TRVs. I also tried vtherm for them, but I could not find settings to boost them on each heating cycle. I have also two rooms with an AC and one radiator each.
I like the auto start stop feature of vtherm for the AC devices. But with the hysteresis of 0.5°C it starts only long time after the TRVs are already heating. Actually I use an automation to restart the vtherm, when it ist 0.1°C below the setpoint and only use the auto stop part of this feature. I don't want the TRVs heat before the ACs, since they are much more energy efficient.
Since there is already a configuration page for the auto start stop feature, I just thought it would be possible to add the algorithm's parameter to the configuration script, but of course, I can also stay with my automation.

Best regards,
Michael