Charged a 12 Seer Rheem in the beginning of the summer, everything worked great no problems. This week I get a call that the system isn’t cooling again. Came to the unit to find that the manual high pressure safety switch was tripped. Put my gauges on the unit, pushed the button and the head pressure went right up and tripped the switch again. Jumped out the switch and let the system run, it hit about 350 head and started coming down, maintaining 200. Let it run for a bit tried it again, head pressure goes very high but then comes down after a few seconds and maintains. Anyone ever see this? Do you think there is a small amount of air in the system? I put an auto reset pressure switch so that the customer can have air should it trip again.