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Monday, October 26, 2009

Exasperating Tank Odors

We have had a problem with our Itasca having a sewer smell. The sewer gas build-up is so strong that we had to leave and go to a motel in the middle of the night and it also sets off the LP gas detector. We dumped, flushed, added extra chemicals, bleached, and everything that we could think of. Do you have any suggestions for us?
Shirley, (Colusa, CA)

Shirley, holding tank odors can indeed be exasperating. One important thing to check on your unit; remove the roof vent caps, (many simply twist off), for each holding tank from on top of the RV. Look for an oversized hole drilled through the roof, one that is way too large for the actual diameter of the pipe. I have found that, oftentimes, builders drill or cut such an oversized hole to make it easier to install the plumbing. It is imperative that you seal this gap around the pipe to prevent odors from escaping the pipe, bouncing off the underside of the vent covers and back down into the actual ceiling of the RV. Trapped holding tank odors will simply permeate through the RV and maintain a presence since the gasses will continue to be manufactured in the tank.

For improving upon the design elements of something as nondescript as a sewer vent, you may want to check out a product on the market called the Xtreme Vent; http://www.coilnwrap.com/more/Xtreme-Vents.htm. I'm a big fan of using them on both black and gray holding tank vents.

And rather than masking odors from the holding tanks, I recommend using a biological additive, one that employs live bacteria to literally eliminate the odor-causing molecules themselves. Many suppliers have now produced such an enzyme-based additive. Avoid using any "chemical" in the holding tanks, especially those that contain formaldehyde. Detergents and some ammonia products may damage seals in the termination valves.

Contrary to what even I have expounded in the past, also avoid home brews. Realize suppliers spend lots of money on R&D, so why risk the integrity of the RV waste system for the sake of a few dollars. Once you switch over to the live "bugs," further use of other types of deodorants and/or detergents will likely kill the good bacteria and defeat the purpose.

As for evacuating the tanks, many RVers completely close the black water tank and evacuate when it approaches full capacity while leaving the gray water valve fully open so bath and kitchen water freely drains the entire time. The drawback to this method is that obnoxious odors can and will proliferate and emanate from the gray tank quite rapidly. I support the method of keeping both container valves fully closed and evacuating each when almost full and using the live bacteria additive in each tank.


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