[GBR]

Speaking from experience and online discussions with Keystone, I was advised that when they drill out the tanks for sink connections if the plug falls in the tank they do not remove it. I found this out when my sink did not drain and the drain line connection failed and overflowed in the belly. I then removed the belly, took the valve connection off and there was the piece of tank snuggly in the valve opening. I was under warranty at the time but I could not get into a dealer while in Florida for a month. Had them reconnect the tank to galley drain when I got back. Good luck.