GM Heads Overflowing Even With Thruhulls Closed!

[stormchaser]

Boat is WAY LOW in the water due to the weight of 15" of HEAVY WET snow (a lot more to come). We're clearing the show as best we can. I'm thinking the water is flowing through the pumps somehow...so I closed the thruhulls/intakes...and its still coming in. HELP!

 

[stormchaser]

Could the water be coming in from the discharge up at the bow?

 

[stormchaser]

OK, phew...that seems to be it, she was/is low at the bow. Closed the OUTPUT thru-hull and the water is no longer coming in. What a PITA. I have never seen this on any boat I've owned...but glad it was easy enough to figure out. Hopefully when we get the baot cleared, we can open the thruhulls so we can use the heads.

 

[Beckytek]

If the water is coming from the bow outlet, you should have a Y valve to switch the output to the holding tank. I would get a shop vac or a small hand pump to remove the water from the toilets and send it over board. Depending on how fast it is coming in. I don't have the GM toilets so I'm not familiar with your set-up. Sorry I can't help more.

 

[Canuck Dennis]

And if the vent from the holding tk. is not plumbed properly, you may fill up the holding tank with the outside water...a boat can actually sink from that, just trace the system out and if a joker valve fails in a head....glug..glug..glug...

 

[Brian Degulis]

Unless all your heads are very low you should be able to open the input and overboard discharge on the highest head and use that untill you get the the snow off? Otherwise your going to be full of Sh#@%t before the day is out. Oh wait a minute that's not a problem for you.

SORRY STROMY I COULDN'T RESIST


Brian

 

[stormchaser]

haha, thanks. Now, if I understand my setup correctly, there is an intake for each head, close to the pump, and there is a single discharge, forward next to the holding tank. Right now what I'm doing is only opening vales when we actually have to go, then closing after use. That seems to be working good for now. I know we're sitting LOW, the boot strip is under water! We've gotten over 30" so far and its still coming down at at rate of over 1.5-2" per hour. I've had to shovel off the boat 6 or 7 times to keep her level (she develops a list to port due to being somewhat protected by the shed/covered slip on one side, I'm on the T-head).

 

[REBrueckner]

I'm surprised snow would weigh enough to cause that problem. I've had several boats in water all winter, lots of snow, and never an issue.

Are your fuel and water tanks full? Seems like 700 or so gallons of fuel and 250 or so gallons of water at roughly 8 lbs/gal, close to 8,000 lbs would weigh more than snow...and maybe the combination is an issue....You in fresh water where you boat might float a bit lower??

You might consider raising a head a few inches if this is expected to repeat...A checkvalve is another possibility but not one I'd suggest since it would likely catch crud on the way out and end up slightly open in your current situation...

Years ago the stern of a boat I was anchored with drifted to the beach, and with the stern about three fee high and the bow poking down in the water, the forward toilet overflowed...and the sound of the running water awakened me.
I too had to shut off the toilet seacocks and all was well after the tide came back in...

 

[Pascal]

Yes each pump has it's own intake seacock, close to the pump.

For water to come in thru the discharge you d have to be dumping overboard, if you are using the tank you shouldn't have any ways for water to come in

 

[stormchaser]

Yeah, I'm surprised too, but it is most definitely flowing back through the discharge, which is now closed and no more problems. Thinks that means the discharge or intake stators need replacing? the foreward thead did not overlow, only the mid and aft.

Yes, I have nearly full fuel and nearly full water, and I'm likely one of the heaviest 53MYs around. We have full live aboard stuff including a cast iron and tile fire pit on the aft deck, a full sized all stainless Weber gas grill on the flybridge, a lazyboy recliner couch in the salon, a 42" plasma in a lift cabinet in the salon, a 32" LCD in the master, and an over-sized Fisher-Paykel stainless fridge/freezer. So, yeah, we ARE heavy...but I never thought it would cause problems switht he heads overflowing.

Now this is an unprecedented storm, 30+ inches of HEAVY WET snow. Ive done my best to shovel, but it is building up a lot in corners and hard to shovel places...

 

[Brian Degulis]

The GM will let water come thru the intake thru hull if the bowl is lower than the waterline or in rough seas were the bowl gets lower at times. I don't know your design but as I said earlier if you have on head that's higher than the others you should be able to use it.


Brian

 

[TopHattandTails]

Dave,
This past summer I was filling my fwd holding tank with water via the GM pump for the fwd head. The pump in the stbd ER and the aft Mst stateroom both had the primer valves / copper tubes removed and disconnected. However, the GM pump in the outboard port side of the genny room (for the fed head) still had the copper primer valve attached (it was actually bent outboard of the pump and along side the pump (tough the see unless you got behind th pump). Check that thing and see if its still connected. If it is remove and screw in some npt bolts in the fitting. Sounds also like the fwd Y valve may be opened to overboard. Might want to think about shrink wrapping (clear would let you see out still) next winter - isn't this the 2nd big storm for you? Good luck!

 

[Tim Powell]

Yeah, I'm surprised too, but it is most definitely flowing back through the discharge, which is now closed and no more problems. Thinks that means the discharge or intake stators need replacing? the foreward thead did not overlow, only the mid and aft.

Yes, I have nearly full fuel and nearly full water, and I'm likely one of the heaviest 53MYs around. We have full live aboard stuff including a cast iron and tile fire pit on the aft deck, a full sized all stainless Weber gas grill on the flybridge, a lazyboy recliner couch in the salon, a 42" plasma in a lift cabinet in the salon, a 32" LCD in the master, and an over-sized Fisher-Paykel stainless fridge/freezer. So, yeah, we ARE heavy...but I never thought it would cause problems switht he heads overflowing.

Now this is an unprecedented storm, 30+ inches of HEAVY WET snow. Ive done my best to shovel, but it is building up a lot in corners and hard to shovel places...[/QUOT

MY HART GOES OUT FOR YOU WE ARE GETTING THE RAIN PART OF THE STORM HERE IN N.C. THE GROUND IS ROTTEN..30 INCHES THAT CROTCH HI THAT IS LIKE GIRAFFE NUTS KINDA HIGH... TIM

 

[SKYCHENEY]

Each head has it's own intake and discharge thru hull. The fwd ones you have found. The mid are both in the stbd ER and the aft are below the stbd drawers in the aft stateroom.

 

[stormchaser]

OK, gotta find the discharge thru-hulls for the mid and rear. But for now, all is good, shoveling the snow seems to have stopped the overflow.

 

[SKYCHENEY]

Pull the hatch in front of the stbd engine and you will see the thru hull and the y-valve for the mid. Open the cabinet door just aft of the master head and you will see the ones for the master head.

 

[stormchaser]

Found them, thanks! I had found the intakes but somehow hadnt seen the discharges.

 

[Canuck Dennis]

Well, to see the discharge you have to go into the water and watch for the shit coming out the side...geee.. didn't you know that....lol...
Cheer up..your are not sinking ..

 

[Red Hatt]

I bet next winter you will try to get a covered shed to keep the boat in. I have been lucky to be able to keep my boat in a boat house from Oct thru April. Good Luck and stay warm. Be carefull and don't slip and fall in the water.

 

[stormchaser]

I tried this year and not a single covered slip was available. But I sure as heck will be shrink-wrapping the fly-bridge next fall. I figured no big deal and that I'd want to use the grill some over the winter. I was wrong, its been a PITA and I've only used the grill 2x over the winter.