@DialMforMarius I have exactly the same problem. The thermostat is installed properly and it closes completely most of the time. About every hour it opens the valve for a short time, which heats the radiator but just a little.

I cannot understand this behaviour at all. In my case the the frost protection is set to default ( 5°C ) and the actual temperature is somehting around 19 °C to 20 °C so there is no need at all to make these little unnecessary heating bursts. This makes also no difference if you tap the thermostat on or off. It will always continue to heat even the frost protection threshold is not even nearly reached (+15 °C).

@Solla-topee Please reprogram the firmware and bring an update soon so that the heater is off when it is really off, and only heats when the temperature is CLOSE to the frost protection threshold.

A "smart" thermostat that heats all year round is not quite useful.

  @DialMforMarius 

I've done the calibration already several times. Every time I checked the vavlue if it installed properly because of this behvaiour. And I can say it is. It is mounted on a m30 thread and tight so this is not the problem. Now it is proberly installed since a couple of days and calibration has been done. It is possible for the device to completely shut the valvue so there is no mechanical issue.

On Off? One can clearly hear the motor rotating and then the heating starts for 2 minutes. It actually just did it right now while I am typing this. The power is set off in the Kasa App and Frost Protection still set to 5°C. The current temperature was 19.8°C, so it is actually super far away from the threshold.

So one can also see the behaviour in the graphs: Heating on an set to 6°C:

Thermostat set OFF and Frost Protection to 5°C:

  @Solla-topee 

Sure I can share the last couple of days if it helps to improve:

In the picture of the 6th you can see the moment, when I wrote the last time. The first peak is the random opening of the valve. The second peak is the moment after I did the calibration again, as you recommended. And then you see the third peak occurring, again a random opening of the valve.

 I only have one device here so there is no second one yet. if this behavior continues i am clearly not getting another one.

The motor rotation means: the radiator is cold motor is opening the valve, one can hear the heating starts and i gets warm.

I will send you the detials in PN.

  @DialMforMarius  Thank you very much.

Meanwhile I put the device in sleep mode and can say I don't have these random heating peaks anymore. However, I guess sleep mode will not do anything else, so it would be nice to have  this behaviour in the normal mode when the temperature is far from any set threshold (FR or manual set heating temperature).

I will wait for the update and check it out again.