That's how I found out I had a leak in my FW this spring when I sanitized the water system. Finally got all the spigots turned off and then the pump would cycle for just a bit periodically. Walked around the outside of the FW to see if there was anything outside turned on and as I was getting into the FW, noticed a bunch of water on the floor coming out from under the sink. Turned out I had left some water in the faucet of the outside sink and the plastic pipe cracked. What a mess, but fortunately only "fresh" water, not gray or black.