holding tank back flow

[Ken Heyman]

Yesterday I noticed that our head toilet bowl was full with holding tank water. Fortunately it was recently pumped so its relatively "clean' and deodorized. The water in the bowl is definitely from the tank as it is the color of additive not the color of sea water. It seems that I can prevent the back flow by keeping the pump handle in the up position. Any quick fixes or do i have to "operate"

Happy Holiday week-end,

Ken

[Jeff Kaplan]

ken, make sure the 1 1/2"  vented loop is working properly and not clogged. this prevents water from coming back. check the nut at the top, contains a little rubber piece, i forgot the exact name for it. start here first. fortunately your water was clean or it would be a big mess...jeff

[Jeff Kaplan]

ken, just a follow up, rubber piece is called a duck bill and can be bought as a new cap/duck bill kit, wm# 594127...jeff

[Ken Heyman]

Thanks Jeff,

I'll check it later today & pick up part at WM on the way to the boat.

Ken

[Rick Johnson]

Ken, if I understand your problem I would think you have a bad joker valve (this might be the same as what Jeff referred to as a "duck bill").  Joker Valve, West Marine part number 127789, manufacture part number 29092-1000, cost $10.99.  If the rubber joker valve is worn-out you might also need to rebuild the entire head - Repair Kit, West Marine part number 223935, manufacture part number 29101-0000, Cost $87.99.  Peggy Hill (The Head Mistress) has suggested in the past buying a new head due to the high cost of rebuilding vs a brand new head ($139.99).  I have rebuilt mine and keep a spare joker valve on board for emergency.

Cheers

[Jeff Kaplan]

ken, that was not what i was refering to. the joker valve is in the head, the duck bill is in the vented loop...jeff

[Rick Johnson]

Jeff thanks, once again I learn something new.     I never knew there was a valve in the vented loop!

[jrmiller]

Hi,
I have had this problem too and discovered that the holding tank vent was blocked (webby crap left by spiders). In any case, whenever the vent was blocked, the head would slowly fill up with water. In my particular case, the water intake line is permanently disconnected, we add fresh water using the showerhead in the sink. Hence, the only source of the water showing up in the head was the tank. After clearing the vent 3 or 4 times a season, I finally rerouted the vent from the stantion tube to a thru-deck screened vent. This solved the problem for me, check your vent.

John Miller

[Chris Martinson]

John:

This is a side question.....I have had problems with my head and believe it is the vent line clogging or water trapped it as it lays on top of the tank because there is no slope for drainage which causes back pressure and a foul smell at the vent and inside..... can you give me some details on how you rerouted your vent?  I have wanted to do it but am not comfortable drilling thru the hull and don't know what hardware to use on the deck to prevent a tripping hazard etc....thanks

Chris Martinson
More Therapy
Hull # 945

[Roc]

Chris,
You wouldn't want to put a vent on the deck.  What you could do is drill a hole below the rub rail (right above or below the sheer stripe).  You don't want it amidships, but either forward of aft, so when heeling, there is less of a chance for the water to siphon into the vent.  I put in an additiona large (1") vent line to help with the aerobic bacteria activity, which is the best way to stop odor.  I routed the line forward and out the side, by the stripe, about where the first stanchion is.  I drilled a hole into the holding tank inpection cover (figured if something went wrong, all I would do is buy a new cover).  I threaded an elbow into the hole in the cover that hooks up to the vent hose.

[Jeff Kaplan]

chris, when i replaced the entire sanitation system last year, i had to reroute the vent line, as the po had removed it from the stanchion post and ran about 20' of cheap vent hose aft and vented out of the cng vent on the transom. i drilled thru the deck, right in front of the stanchion post,about 3"fore.  i thought of drilling thru the hull, which many do, but i opted to go thru deck. i put a clamshell over the new vent to keep water out and it is close to the toe rail so nobody can stub their toes. i got this idea from peggy hall and it works great. if you go thru the hull, put a clamshell over it also,to keep water from coming in when heeling. i increased the vent hose to 7/8" and the thruhull was 1". i used a 1 1/16 holesaw,bedded it down and good to go.pretty easy job but be careful when drilling not to hit any wires.good luck...jeff

[Chris Martinson]

Roc and Jeff:

Thank you for the info - I'll figure out which is best and what I am able to while I'm in the water.....if I can get the nerve to drill thru the hull or deck.

Chris

[Roc]

Chris, the first hole is the hardest to drill.  After that, it's not so bad.  I actually saved all the holes I have drilled, for one reason or another.  I have an old tool box full of holes!  I bet I have at least a couple dozen!!!!   

[Stu Jackson]

Buy and read Peggie Hall's BOOK.