Mysterious kitchen flood

[dm59]

We just had a very strange accident. Went away on vacation for five days and came back to find the kitchen floor flooded. Water went down through the floor into our finished basement, much of the ceiling and carpeting there ruined. What makes it strange is that no one (including a plumber I called and the restoration services people) can understand what happened. No broken or leaking pipes. The water seemed to come from where the dishwasher is standing, yet no one had started the dishwasher before we left or set the delay wash, and we've run the dishwasher since we've been back with no problems. Moreover, before we left on vacation, I shut the main water valve off (just in case). According to the plumber, there must've been at least 30 gallons of water spilled (based on the damage) -- a lot more than a dishwasher would use. The plumber is convinced that the water came from the dishwasher (the door seal at the bottom is all wet), yet even he can't understand how and why so much.

There is nothing else that anyone suspects. The refrigerator is on the other side of the kitchen and it was dry around it. It didn't rain at all while we were gone, so it couldn't be anything like that.

Any ideas how a seemingly normal dishwasher with the main water supply shut off can, all of a sudden, go berserk, and then return to normal operations when we came back?

Thanks!

 

[johnjh2o]

30 gallons of water is more water then the dishwasher could have used on one cycle. Where did you turn the water off? If it was the main valve it's not holding. Do you have AC or a water softener?

John

 

[dm59]

I did turn the water off at the main valve, and it is true that the valve may not be holding (I tried today and kept getting a small trickle); however, still so much water? And why would it somehow get into the dishwasher and then escape it? No water softener; I do have a reverse osmosis system, but it was dry around it. The AC's exchanger and drains are nowhere near the kitchen.

 

[johnjh2o]

What type RO system do you have? Is there a pump on it or does it just work on house pressure? In any case check it out very closely.

John