Unit - WIF. Refrigerant - 404A. Remote condenser through the roof. Your typical setup.
This thing is losing 10lbs every other frikkin day. It takes 20. This %^**&%# leak should be blowing my hat off, yet I have been back on this thing with several other techs.
Dye. Electronic leak detector. Nitrogen to 200#, which holds. Evacuation to 600 microns, which holds. We've pulled off every stitch of insulation and traced every inch of piping. At one point three of us were on site - one on the roof, one under the ceiling, one in the evap.
There is no pressure relief. I've thought the leak may be coming from the high pressure control - thinking once it hits a certain pressure, it blows the charge, then resets, but we've blocked the coil and ran the head right at the tripping point and nothing.
I'm convinced someone is sneaking in there and blowing off the charge.