With a chiller system air temp readings at the air handler isn’t that important as it is completely dependent on the chilled water temp. to cool the boat properly, it needs to be below 50 degrees and during the day all three chillers need to be on to get there. One critical factor is sea water temperatures. When i run pump nr 1 with the new impeller above but eroded body, coil temps are 5 degrees higher than on pump nr 2, condition unknown. Not a big difference in amps though , at most 1 amp per chiller, but it seems like the breaker holds longer At this point, i need to get the pumps rebuilt or replaced.