Problems with ZWave Thermostatic Valve ZWA021


I’m having problems with the ZWA021 Valves, which is i think unrelated with HA itself, but I’m hoping someone here uses them also and may have an idea.

I have 6 valves in my home 4 of which are automated (having simple night/day temperatures set). Few times a week one of the automated valves will behave like this:

During the day the tempreture is set to 12.0, then I heat for the night at 17.0 until next morning. But as you can see around 01:00am the tempreture jumps to around 20.5 and the heater stays fully open (I assume, its very hot) without any regulation afterwards. It will stay that way until I intevene and what I do is that I set it on “Boost” and after few seconds turn the boost off. It then closes the valve completely and everything goes back to normal. I always check LCD at such time and it is showing 17.0 normally.

Did anyone also had such issues? Is this a faulty unit? This happened also in each of the other rooms I have automated but in this one it happens most often (this is the furthest unit from controller) but I somehow doubt this is related with ZWave controller or HA itself. But its hard for me to believe that all valves are faulty so I’m clueless.