Community Forums

Kaelinsdad · 08-12-2014, 04:05 PM

I cannot seem to located the source of black water tank odor in my motorhome. The tanks are dumped, rinsed well and treated with deodorizer but still have strong odor if left closed up for any length of time. Is it possible that a vent stack is broken or come loose? Is there any product on the market such as a smoke generator to visually find a leak in a vented system? Any other ideas would be appreciated!

Sky_Boss · 08-12-2014, 04:22 PM

Can you localize where the odor is coming from? Is this a problem when stored inside or does all the odor originate from inside the coach?

Make sure all of your all p-traps have water. The sneaky one to double check is your washer hook up. If you have one but don't use it could easily cause a dry P-trap. If that is the case you will want to occasionally add water to that p-trap.

After that you could check your roof vents anything that might be blocking the air flow. Of course, it could be possible you have a busted vent pipe but I think that is unusual.

Also make sure your toilet holds water. If it is draining it would allow gas to back up into the house once it dries out.

Old Radios · 08-12-2014, 07:33 PM

Check the bathroom sink trap also and make sure it has water. Sometimes that goes to the black tank, not the gray.

Bad Bolt · 08-12-2014, 10:47 PM

I just finished a pretty major bathroom floor repair due to a leaky plastic part behind the toilet. Dealer called it a vacuum break. The sinister thing is the it leaked only enough to drip down the back of the toilet and work its way to the wood below the tile. Over the years, it completely softened the toilet base in an eight inch radius.

This caused the rubber black tank flange gasket to fail letting noxious gasses into the coach.

Does your toilet wabble?

Do yourself a favor and just remove the toilet and fully inspect the rubber gasket, flange and floor. It's good practice and also teaches you about this very critical part of coach ownership.

Make sure you dump and fully rinse your black tank before removing the toilet. I also suggest filling the black tank 1/4 full of fresh water and add the treatment. It makes a huge difference in the smell factor.

SarahW · 08-12-2014, 11:06 PM

I'll just chime in that if the smell is like rotten eggs, check your batteries.

Oh--and welcome to the forum!

AFChap · 08-13-2014, 07:02 AM

Gray odor can be mistaken for black. There are vacuum breakers in the plumbing under each sink at the top of a vertical pipe. The can stick open and let tank odors in. The can be cleaned up or easily replaced.