Simple install mistake explains why 3-month-old heat pump gets rusty, leaks

Simple install mistake explains why 3-month-old heat pump gets rusty, leaks

A homeowner in Pennsylvania turned to Reddit after spotting rust on a Mitsubishi Hyper Heat outdoor unit that was only three months old. What came back was a reminder that even high-efficiency home upgrades can be undermined by a single installation mistake. What happened? Before the rust question was resolved, the homeowner said a technician had already identified "there is an oil and refrigerant leak" and planned to pressure test the system, f…