Rob D and Ferb came out from Gem Heating and Plumbing and figured out where the leak in our a/c heat pump system was, and was able to fix it after three years of struggling with another company. They seem to really know the Mini-split condenser systems. Ours is Fujitsu, but I think Mitsubishi and others are substantially similar. I don't know how their prices compare to others because our original seller footed the bill for this longstanding problem. Thanks Gem.