So what you can see here in this setup is the version that i tried. The pressureswitch is really really close to sensor ( in height difference ) . That had two reasons. One was that i wanted to increase responsitivity and the other there wasnt’t more space because i had to close the window :). The result is that it is too close. A distance of min. 10 cm from the sensor underside to the switch should be. Otherwise there is no real ” work” done ( in terms of thermodynamik “work” not that of karl marx ) and the sensor will not switch on or off.