Winter is coming here in the Netherlands and I am working on my cabin heating to start working again. I / we think the 400v controller is working fine, but the PTC heater is not working as it should be working. So we did some more research on the wiring to the PTC heater: We are measuring around 390 ohms (on the red dots), and it should be around 70 ohms to get enough power at 400V. The other pins (blue dots) are shorted. We think this should be correct? Is it? (the PTC heater was at ambient temperature) Besides this I think there could be something wrong with a sensor that is malfunctioning and causing the heating control to think it too hot, like CSPHD mentioned here: Heating system has stopped functioning And John here: Heating system has stopped functioning Is there anyone who van measure the impedance of the PTC heater? My next step will be to take a better look at the HVAC assembly, but it would be great to get more info first. Thanks!