Holding tank

[Roxanne]

my husband and I purchased a 1999 Carver 356. I feel like I'm pretty boat smart but this has me stumped. He is out of the country this summer and I decided to do some good spring cleaning. While cleaning the aft air conditioning ventsp I noticed the holding tank is full. Maybe 2 to 3 inches from the top. This explains A LOT since this is not our first Carver and our old Carver only had 1 tank that we didn't pump out more than about once a month. This boat is always full of Poo! I went back to the pump out station and pumped both tanks. I stopped several times to get the system to build up more suction but it seems like it is empty. When I go look however it is far from empty! I looked all through the mounds of paperwork that came in the Carver "suitcase" but all of the diagrams and schematics are on the 355 model and don't look anything like our layout. I was thinking of reasons this might happen and all I can come up with is thAt maybe the vent is blocked. Wouldn't the vent need to be open to suck out the poo? Doesn't air have to replace the contents? I looked for the air vent for the tank but I'm not sure which one it is? I tried to look for the air vent by following it from the tank but wow that space is small. The holding tank is literally an inch from the air return Everything else works fine with the sanatation system. Thanks for any thoughts. It's a gross thought to have so much crap in the boat that I can't get rid of!

[mjk1040]

Can u take the vent line off at the tank and blow air or water out of it. It appears the vent is on the port (left) side of the boat next to the floor drain behind the ice maker. I believe your theory of air in as contents out. I don't think you can run anything from the vent bank to the tank because they loop the hose at the vent outlet. Go to the Carver Yacht site, they have diagrams for the 1999 356 under owners section in parts. The 355 paperwork should match the 356, but even that sometimes is not exact. A bug may have plugged the vent. Good luck!

[Viper]

Welcome aboard. You've come to the right place for Carver help. I applaud you for tackling this yourself.

A venting issue is a possibility. If you have an overboard discharge option, some are plumbed in a way that incorporates a 3-way valve in the output side of the tank. If this is the case with you and the valve is switched to the overboard side, you won't be able to pump it out through the deck fitting.

Have you confirmed there actually is waste in the tank and that you're not simply looking at a sludge build up on the tank walls?

[bud37]

To add to all of the above, another visual clue might be to look at the tank and see if there is any evidence of it being deformed ( as in sucked in a bit ).....this would tell me the vent was plugged or restricted......vacuum is quite powerful.

[Roxanne]

Thanks Mike! I have spent about 20 minutes looking for then vet on this tank. I looked up the makers of the holding tank and going off the diagram on their website I should be able to see it but I don't. I tried to unscrew the top of the bed frame thinking I would get a better view of the situation but that is not the case. I am not sure how they got all of this in this compartment but I am sure it was easier when they were assembling it than it is now! If I can't find the vent before my husband Mike gets home, do you think I can untwist the screw on top of the tank itself and try vacuuming it out again? At least I might be able to get it cleaned out? Thanks so much for your help.

[Samuel]

http://www.carveryachts.com/media/3882/ ... ual_99.pdf This should
help you.

[Samuel]

You should have 2 tanks the one in the aft cabin is under the rug remove floor board. If it is dark it can be empty i put hot water in mine fill it up add blue chemical in it and take a ride. Then go empty tank.

[Roxanne]

The tank itself is a little swollen looking. It might be my imagination since I've figured out what is in it and how long it must have been in it. It does not appear to be concave however. Last Sunday before Mike left town we pumped out and he left the vacuum on a few seconds just to make sure nothing else was coming out. Twice there was a strange pop noise that neither of us could identify. I have never heard it before on this boat but now that we are talking about it maybe it was the tank trying to re-pressurize ?? Like if you suck the last of some Coke out of a bottle and you continue to suck the bottle shrinks in but when you release it it pops back out? Another thing, I read on someone else's thread that the vent on this tank is on the back, or where my head would be when sleeping on the bed. He had a reply that spoke of the tank leaking into the filter if the tank is more than 2/3 full and you take the boat out, when you reach plane the tank contents runs back through the air filter and clogs or blocks it? True? The manufacturer of the tank shows the air exhaust at the front but this boat is 17 years old. Maybe I'm looking in the wrong place.

[Roxanne]

Samuel, thanks. The front tank is fine. It empties out completely and it's what the girls and I are using now. As I was doing spring cleaning I decided to wax our new boat. Turns out she's not white at all. She's cream or off white. I'll be living here this summer finishing this project!! Before/after pic. I'm screwed. I should have left it oxidation white color LOL.

[Roxanne]

Ahhhhh