Water Backing Up Galley Drain

[sandycohen]

Hi Everyone -

When I get back to the dock, if I have put the rail in the water I'll find a small amount of water in the galley and head sinks. The thru-hull valves (ball valves) are closed. Any ideas where this water is coming from?

Thanks

[svHyLyte]

When you close your thru-hulls, some of the water trapped in the drain above the thru-hull might run back into the sink if the trap is close to the level of the waterline. Altenately, your thru-hull might not actually be closing or fully closing, even though you are turning the handle (I have seen this before). As a test for that, "close" the thru hull and fill the sink and let the thing sit for a while. If the water level in the sink falls, you have the second issue.

FWIW...

[sandycohen]

Gotcha - will try that, thanks!! if they leak they don't leak fast because the water sitting in the draink when i go below has had at least 15 minutes of flat motoring to 'leak back out' the drain

[Leventdelamort]

Check and see if you have a anti-siphon device, or a vented loop in your drain system. Under certian condition water can return via that routel

[Christian Van H]

Originally Posted by Leventdelamort

Check and see if you have a anti-siphon device, or a vented loop in your drain system. Under certian condition water can return via that routel

I don't believe you can have a vented loop in a gravity drain galley sink situation. In order for a vented loop to work, the loop must be above the waterline, so no water would ever flow "up" and then down. Only drains using a pump might have this system. HyLyte hit the nail on the head. Remember, when you close the seacock, you capture all the water above the seacock up to the waterline. Then, when you heel, that water pours out into the sink. C

[senormechanico]

The water between the faucet valves and the end of the sink spigot might be "falling" out when the boat's heeled.

[sabray]

maybe your cranking along rails down and the water is presurized against the not completely sealed seacock?