Mystery water in my gray tank!

[kkochner]

Does anyone have any ideas on how my gray keeps filling up when everything on my boat is off? I drained my fresh water tanks and turned my water pump off and some how my gray tank is still filling up with water!

I have looked and watched it and there is no water actively draining into it...is it possible that it is somehow back filling sea water?

My gray sump pump is currently not working...could that be letting water back flow in?

Any experience or advice greatly appreciated...thanks!

[Viper]

Is your AC/Heat on? Their condensate they will drain into the sump.

[bud37]

Source of the post My gray sump pump is currently not working...could that be letting water back flow in?

If that pump feeds grey water out below the waterline I would think your idea of a backfeed is reasonable in my opinion.......have a real good look at the system........good luck .

[Viking-boater]

On my 2006 Voyager 46 there is a check valve inside the grey water tank on the output hose coming from the pump. That is required as the aft port side output under swim platform is at or below water line. You may need to replace that check valve. Maybe get 10 or more friends to stand on bow of boat to get that output above water line. If not you may me surprised on how fast the water flows into the grey water tank when you remove that check valve for replacement !