Vital to the operation of the refrigeration cycle, superheat must be maintained and stable to protect the compressor. We all know that the heart of the system cannot compress liquid (slug) without bad things happening. This would represent low/no superheat. But, did you know high superheat can cause valve and compressor problems as well? No matter the reason for attaching your gauges to the system, you must check the superheat, in the air-conditioning cycle.