looking for suggestions on how to snake the septic holding tank vent line. Raritain toliet is burping and the stateroom where the tank is smells like ****!
First make sure you don't have a charcoal filter on the vent line... follow the vent from the tabk to its fitting on the hull. Charcoal filters are great at eliminating odors outside when flushing but if the tank ever gets full the filter gets wet, the charcoal clogs up and air can't go thru As a result flushing results in the tank getting pressurized which you can confirm by slowly opening the pump out fitting. If your vent filter was clogged the tank could have been damaged by being pressurized. Often when that happens the problem is at the sender for the gauge which will let air escape in whatever space the tank is located Another issue could be some blockage at the vent fitting itself. Sometimes there is a mesh screen there that gets corroded or clogged Otherwise there shouldn't be any need to snake the vent hose
I will hunt for the filter. One would assume the filter would be visible somewhere accessible? If filter is not visible, how about using a garden hose from the outside to clean vent line?
IF there's no in-line filter (or IF you remove it temporarily and replace with a filler section of hose)... and IF the holding tank is relatively empty... and IF you open the pump-out fitting first... and IF there's no mesh screen on the vent hose (or IF you remove it if one exists)... MAYBE short bursts of water as from a pressure washer MIGHT have some benefit. -Chris
I've had 3 boats recently with the same problem. One had a clogged charcoal vent filter and the 2 others had the 90 degree vent fitting on top of the tank plugged. The first one of those had me stymied as the vent hose to the outside was clear but the tank wasn't venting. As it turned out it was the plugged fitting that was the culprit.
Normally the charcoal filters are installed high along the hull. Depends on the layout but often behind panels in closets. If you have one you cannot back flush the vent hose or the filter will clog.
This, follow the hose from the tank to the vent. Use your camera phone to take pictures in areas that aren't easily accessable.
My $0.02. I'm not familiar with the Raritan brand products, but I've experienced a similar problem on my Headhunters that traced back to the anti-siphon valve [vented loop]. The gasket on the vent cap had gotten old and was not keeping a good seal. Replaced the vent cap and problem solved.
When it doubt, pull the hose off the tank and send dock water back. Never apply any pressure to any tank.