Today I arrived and met with the homeowner. I completed the evaluation today, began by verifying system safety and its performance. I then flushed and treated the indoor water removal system. While servicing the outdoor system I cleaned the electrical cabinet and washed the unit using water. As I was indoor I noticed the temperature differential was lower than average, this led me to watch pressures outside closely during operation. After about 20 minutes of run time I’ve observed a concern that indicates the main refrigerant pressure control valve is either under feeding or beginning to stick explaining why I had a lower temperature differential at indoor unit. I went over options with customer and he wants to go over them with his wife to make a decision on which repair option to move forward with.