I know that it is not related to the AC unit or the water heater.
Use type K fittings and tube as they have the most wall thickness, and tend to be as drawn instead of annealed.
u have a major leak,call a repairman.
You have a leak. Have a plumber fix it.
I would crawl under house run down the line and see where it goes hope its not your water line. you may have large water bill.
