396 aft holding tank and lines

[geoles297]

Can someone share with me the best way to access the lines under the aft cabin floor to service or replace septic lines. We are at a loss to find where smells are coming from. The vac flush in the forward cabin is fine but the conventional toilet in aft is a problem. Other wise the 396 is a great boat. Thanks George

[AaHubb]

On my 404 there are access panels under the carpet in the aft cabin. Only part of the carpet is glued down, the rest can be pulled back to gain access to the floor panels.
..Aaron

[geoles297]

Thanks it does seam all the carpet is glued down

[DanM]

I replaced my waste lines a few years ago. The previous owner did not empty and flush the tanks as often as they should have been. Once the hoses start to leach you cannot remove the odor unless you change them.The connection between the aft head toilet and the Vacuflush pump runs at the forward end of the aft stateroom and appears to be PVC so changing it is not usually required unless it is cracked. The pump hose connection to the port side of that PVC pipe is forward of the port muffler. You get to it from the head of the bed. It was the meanest part of all of the hose changes since you are on your belly leaning as far in as you can, hoping to be able to reach. I heated the hose with a hair dryer and used dish soap to help ease it on. Don't use a heat gun as you can damage the coating. The job would not be so bad if the waste hoses were not heavily coated and stiff but that keeps the odors contained. You need to also make sure the relief diaphragm on the top of the tank is clean and seats well and the foam cover is cleaned and odor free. Lastly check the connection between the hoses and the tank vent filter to make sure they are snug. A loose fitting (or one with a bad gasket) will allow the gasses to escape into the room. If the vent filter has gotten wet due to an over full tank or during the flushing process you may need to change it. They recommend you change them every season. I make my own for about $20 each rather than pay the $115 at the store.

Good luck,

Dan

[Tx5311]

Dan M. I am hoping you will see this and be able to help us. We bought a 2003 Carver 396 MY last year. We are new to this size of boat and to Carver. We are still trying to figure out a number of things. In your post from Jan 17, 2014 you talk about the aft tank relief diaphragm and the foam cover. When we take the foam insert off the top of the tank we see straight through to the tank. Is this normal or is there more to the "relief diaphragm. We noticed foul orders when the head is flushed.

We assume the aft tank is vented to the outside but we cannot locate that vent. Any suggestions? We have looked at the parts manual online without success.

Regards,

Deb and Mark

[bud37]

Welcome to the forum..........I believe you may be talking about the tank relief valve....they can be replaced....google ,dometic tank saver relief valve ...I think that will explain everything for you...it is a vacuum breaker......

http://www.marinesan.com/TankSaver-Reli ... 255247.htm

[DanM]

Bud37 has got it right. If the diaphragm under the foam is missing it must have fallen into the tank since it is on the underside of the valve. Make sure you retrieve it before you put the new valve in. It could get sucked up into the discharge line during a pump out which will create much greater headaches.

Good luck

[Viper]

Source of the post....When we take the foam insert off the top of the tank we see straight through to the tank. Is this normal......

You should not be able to look into it and see the inside of the tank if you're looking into the relief valve unless you removed the valve itself. It's a two piece unit; the tank flange and the valve body that is pushed into the flange. The valve body contains a few parts. Here is an example of the two pieces:
http://www.ardemco.com/accessories/sealand-dometic-313255247-tanksaver-holding-tank-relief-valve/

If the valve is worn, you will get odors in the cabin.

[Tx5311]

Thanks everyone! This info is very helpful. We will check it out.

[mjk1040]

geoles297, Also check that the shower sump isn't the cause of your aft cabin smell. If you use the aft shower sometimes, standing water in the shower sump will begin to smell, the sump box is not sealed. Mike