We were "told" that a full sight glass devoid of bubbles is indicative of a full or charged system. How true is this? Recently I have had an evaporator which iced over very nicely, but the sight glass still showed up half full and bubbling. This was a new installation, mind you, a 1.5 hp hermetic compressor with an externally equalised valve, Danfoss with orifice number 2. Room temperature +1 Celcius and running on R404. Is the orifice perhaps too big , Number 2, or should it have been a number 1. I note in a previous thread that the drier position sgould always point downwards from the receiver.