Thank you, Denny. Do you know how the Isotherm 65 external heat is vented? The Norcold, also supposedly with the same compressor type, and for marine use too, and 2.7 cu ft compared to 2.3, vents out the bottom. I did pull mine and confirm there is no way to add refrigerant or check the high/low pressures. It is a sealed system. If it breaks you toss it. My unit also has the copper oxide on the soldered joints. I just wonder if the Isotherm is better?