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+-- Thread: Too long on a Mini-split (/showthread.php?tid=7379003)
Too long on a Mini-split - MstrCarpenter - 08-05-2025
There's a thread in "off topic" about a refrigerant leak. I just finished one that was a challenge. Doing a pressure test I'd drop from 450 PSI to 445 in about an hour. Three indoor units with no way to isolate them after the line-sets are connected. Been at it almost all day and I haven't found it yet, and now my nitrogen tank is down to 150 PSI. Try another day with a full tank. I disconnected the lines outside one pair at a time and re-tested. On the second set I found the smallest of small leaks inside on a factory flare (a little smaller than I make them) with a tiny scratch. (Probably from their deburring tool.) A new flare and 450 P.S.I for 18 hours proves I got it. Now it's day three when I vacuum down to 300 microns and hold for an hour just to be sure. Open the valves and give it some power to check sub-cooling. Neaten things up and this project is finally done! (Except for a few straps on that liquid- tight.)
B.T.W.; when I left it was holding at 65° inside; over 90° outside.