Holding tank filling with sea water !

[IOLANI]

3/4 full light came on in rapid fashion. Should have been almost empty. Before I realized what was happening the tank filled entirely with sea water. I was able to stop it by shutting off the two through hull fittings that feed the Galley Maid pumps to the V berth and guest heads.

What's going on here is there an internal check valve inside one of the pumps gone bad ?

[jmooney]

You may have a copper line that connects the priming plug holes to one another. This is done to avoid loss of prime issues. However it will fill your holding tank and is usually only used if discharging directly overboard .

[IOLANI]

Thanks I will check that at sunrise. Midnight here I'm just glad I got it stopped at this point.

None of the valves were repositioned since last season and it worked just fine it would take a couple weeks to fill the tank and call the pumper boat.

Just looking at the install diagram could it be a vented loop issue and a siphon occurring ?

[Bob Bradley]

Without knowing the exact design of your installation, I'd check the vented loop first. Perhaps the vent hole or hose is clogged, allowing a siphon condition to exist.

[IOLANI]

Without knowing the exact design of your installation, I'd check the vented loop first. Perhaps the vent hole or hose is clogged, allowing a siphon condition to exist.

Will do Bob thanks. I know there are anti siphon valves on the master and guest heads but don't remember seeing one on the V-berth pump ....