Pressures outside the manufacturer's envelope are an early sign of refrigerant loss.
Superheat tells you whether the evaporator is being properly fed.
Compressor amp draw climbs as bearings wear — a useful predictor of end-of-life.
How to read your HVAC service report
What the pressure readings, superheat figures and amp draws actually mean.
Key answer
What the pressure readings, superheat figures and amp draws actually mean.
More on maintenance