The RV Doctor Recommends Xtreme Vents to Eliminate RV Odor Problems

Questions from concerned RV owners:

1. Dear RV Doctor, we have a severe sewage odor in our 2001 Layton travel trailer. I think the vent is clear of any obstruction plus we've dumped and flushed the holding tank numerous times and used holding tank deodorizer, yet the odor remains. There is no leakage around the toilet. What can I do? Scott Wertz, (Lebanon, PA)

2. Dear Doc, we just bought a coach and there seems to be a smell that comes from the toilet, probably the holding tank, that my wife finds very annoying. Is there anything we can buy to put in the holding tank to eliminate the order? It seems like it's there even when the holding tank is supposedly empty. Please help otherwise I'm afraid my wife will quit riding in the RV before we even take our first trip. By the way we bought the coach used and it's a 2001 Kountry Star. Robert Molina, (Yorktown Heights, NY)

3. Hi Doc, we have a 1981 Triple E Empress bunk bed model C2000 and while we are driving the smell from the toilet is sickening. We have to open the bunk bed window a little so the kids sitting at the table for traveling don't get sick from the smell. We dump it, clean it out, then add liquid deodorizer and yet it still smells terrible. Tom Greaves, (Edmonton, AB)

4. Help! I am relatively new to RVing and one of my developing "pet-peeves" so far is the odor that seems to be coming from our bathroom area. We are using a high-quality black tank deodorizer solution, but when sleeping in the back area at night the odor is sometimes distracting. I keep the vent open at night. Is there anything else I can do? Your help is much appreciated. Dan Biddle, (Folsom, CA)

5. Dear RV Doctor, I own a 1989 Pathfinder and for about two years now when we drive down the road you can smell the holding tank, but when parked you cannot. Do I have a vent problem? Is there something I should be doing? Grant Berry, (Whitecourt, AB)

Hi Gary, we are in an older model 1981 fifth-wheel and experiencing a strong odor inside and outside of the trailer. The black water holding tank or the gray smells of a strong odor. Is there any treatment we can do ourselves to get rid of it? Elaine Godwin, (Arlington, TX)

6. Dear Doc, I can't get rid of the nasty odor from my black holding tank while traveling, unless I have taken the time and effort to rinse it out numerous times to ensure it is totally clean before I leave from the campground. Can you recommend some much needed help? Tom Ward, (Los Angeles, CA)

7. Dear Gary, on our last RV trip, I noticed a foul odor coming from the bathroom sink. I never noticed it on any previous trips. Peering down into the sink I saw four or so inches down what appeared to be standing water as though the sink had a slight obstruction. No obstruction seemed apparent so what gives? Did we encounter bad water along the way or is the grey water tank contaminated? Katy Wells, (Lodi, CA)

8. Dear RV Doctor, sometimes we can smell sewer odor in our lavatory and shower drains after setting all night, regardless if we are hooked up to sewer, with the grey water going straight through, or if the valve is closed and we are holding the grey water. Normally we are fully hooked-up with grey and galley water draining through and the black tank valve closed. Help! Guy Smith, (Tulsa, OK)

9. Hey Doc! I have 1998, 29-foot Class C motorhome (Shasta Cheyenne). My problem is that there is a terrible holding tank odor when driving and only when driving. The black water tank is emptied and flushed on a regular basis and the gray water is left open while parked. I have changed to an organic cleaner or deodorizer, but nothing seems to help. Some relief is had if the roof vent is left slightly open and the fan is on. Any suggestions? Mike Sharp, (Winslow, AZ)

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The RV Doctor responds:

Well readers, can you in any way relate to any of the above posts recently received at the RV Doctor Column? These are but a sampling of those I receive each and every season.

Holding tank odors are a definite problem experienced by the vast majority or RVers. But there is good news; relief is available! By following correct waste management practices, checking for proper venting and by using a few aftermarket products I recommend you can all but eliminate and certainly minimize those dreadful odors that seemingly plague us all.

First, fully realize that odors can originate in either the black water or the gray water holding tank. Foul odor is not limited to the toilet tank only! That said; let’s take a look at a few areas within the RV waste system.

VENTING

One important aspect of proper RV waste management is understanding the dynamics of holding tank venting. Each holding tank must be vented from the holding tank up and through the roof to the outside atmosphere; the typical vent consists of 1-1/2” ABS plastic piping. Here’s an issue – Oftentimes coach manufacturers cut a very large hole in the ceiling and roof for this vent pipe to pass through; it makes the installation a little easier. Sometimes this vent opening may not be sealed properly all the way around the pipe. In other cases the vent pipe itself may not extend far enough above the roof line. According to the NFPA 1192 Standards on Recreational Vehicles, “each vent pipe shall pass through the roof and terminate vertically, undiminished in size, not less than 2-inces above the roof.”

But if you have a short vent pipe (less than 2-inches above the roof), and the area around the pipe is not sealed and an oversized hole exists, then it is entirely possible for tank odors to pass up the vent pipe, hit the roof of the sewer vent cap and bounce back down beside the pipe into the ceiling area where it makes its way to the living area and you inhale the results. Not all tank odors are lighter than air!

So, from the roof, pop off the top of each sewer vent on the rig and be sure the area around the vent pipe is sealed properly (no gaps anywhere around the full circumference of the pipe) and that the pipe itself stands at least two inches above the roof. Extend it by using an ABS coupling and a short piece of pipe if necessary.

In some cases, depending on the method used to connect the vent to the top of the holding tank, vent pipes have fallen down inside the tank, nullifying any venting action whatsoever and allowing tank odors to exhaust well below the roof line, virtually within the ceiling void or even inside an interior wall pocket trapping odors inside the living sections of the RV. By inspecting the vent regularly, this can be avoided.

I actually recommend replacing stock sewer vents with one of my favorite aftermarket,
add-on products; the Xtreme Vent produced by Coil n’ Wrap, (www.coilnwrap.com).

This unique roof vent operates around the Venturi Effect which, in simple terms, states that as air is passed through the vent, it decreases the static atmospheric pressure inside the holding tank and literally draws vapors and subsequent odors out of the tank through the vent pipe.