Foul Air

[silverloaf]

Part of our restoration effort 4 years ago was replacing the 3 roof ventilators. 2 were Fantastic fans and one was an OEM. None of the them worked. I installed MaxxAir 10-speed ventilators. They exhaust a tremendous amount of air and keep our trailer reasonably comfortable in warm weather.

After moving into our trailer for a 3-month stint while our new house is being completed, we began experiencing sewage odors. There were no leaks under the trailer or around the toilet. I have the discharge hose connected directly to a dedicated fitting in our house septic system.

I began to think maybe the ventilators were pulling sewer gas through the traps under the sinks and tub. It sounded rather crazy since the water in the traps are designed to keep gas from escaping from the septic. Nevertheless, I put the drain plug in the tub and closed the sink drain.

It worked! I reversed the process and it was back to foul air. I suspect there isn't much water collected in the traps; the gas was bypassing the water by suction from the ventilators.

As a secondary measure, I began keeping the toilet 1/4-1/3 full after every flush. I crack the flush lever just enough to keep the water in the bowl without opening the discharge valve. It actually helps keep the toilet cleaner.

So, there you have it. Everything you want to know about the dumper in your camper.

[KYAvion]

That’s interesting. Would creating a trap with the stinky slinky work too?

[silverloaf]

Right now, I'm letting the black tank fill to about 60%. I've been adding bacteria pouches when its empty. I'm allowing the bacteria to break down the solids before emptying it into the septic; this keeps any solids from staying solidified in the tank. Then I drain the tank. I'll rinse the hose with some water I've accumulated in the gray tank.

Your idea has merit. I think the odor is coming directly from the septic tank into the gray water plumbing. I always keep the gray valve open. The black tank is out of the loop.

Interestingly, the traps in our trailer are very shallow, unlike the ones used in residential plumbing. I think it's quite possible that the suction from the fans displaces the water in the traps and pulls the gas around it.

I have no other explanation. KY.