Hello,
I have problems with humidity / ice (Asi 178 mmc). An original Zwo dew heater is installed and new desiccant tablets are installed. Is there a sealing gasket installed normally? When I disassemble the front plate from the sensor chamber there is no rubber ring installed ... Maybe this is the problem with frosting sensor? Excuse my bad English.
rubber ring is necessory, did it still in your hand?
If so, I think redry the dessicant and install rubber ring will stop dew issue.
