I have a cold machine on our 34 hunter. It was recharged last year after the compressor was relocated. This year I notice that it runs all of the time. The cold plate gets fairly cold, starting to frost over after about 45 minutes. But the big question is that the return line to the compressor gets covered with a thick layer of ice, mostly at the compressor end. This happens after about 10 hours of operation, and as I mentioned the unit is running constantly . Any idea what is happening here? Thanks, Dave