Sewer odor when towing

[CabinetmakerII]

We have noticed a strong sewer odor inside our 5th wheel when we stop for a break or to set up for the night. I have checked to ensure there is water in the bottom of the stool that creates the seal as well as placing a seal over the shower drain. I have traveled with the bathroom overhead vent open as well as closed. I have replaced the vacuum break under the bathroom sink. I have not done anything with the rooftop vent caps. I am out of ideas as to what could be causing this problem. Any ideas would be appreciated. Thanks in advance
CM

[CabinetmakerII]

I think I have found the source of the odors in our coach while traveling. Apparently the shower P-trap is allowing odors to drift back into the coach. We now place a rubber stopper over the drain which is keeping the odor where it belongs. Thanks everybody for the ideas you presented. Happy and safer travels!

[lane_hog]

Had that problem... Found out our sink was plumbed into the black tank. A $2.00 rubber stopper on a chain for the sink fixed it.

[CabinetmakerII]

OLYLEN wrote:
Do you have a washer dryer combo or the ready to go but not installed. The trap on it installed or not can be a source of the gas. Cap it or fill the trap.

LEN

Thanks Len! Had not thought of that! No WD connected but the prep is there. Gotta clean out the closet to get to it...

[OLYLEN]

Do you have a washer dryer combo or the ready to go but not installed. The trap on it installed or not can be a source of the gas. Cap it or fill the trap.

LEN

[CabinetmakerII]

doxiemom11 wrote:
Air admittance valves can let grey tank odors into the rv and they smell just as bad as the black tank odors. There is usually one under each sink. Cheap and easy to replace - purchase at Lowe's type big box stores around $20. Screw old one out - new one in.

Yes, I have replaced the one under the bathroom sink but not the kitchen. There is also a similar device behind the shower that is for the black water flush system that could also be contributing to the problem. It is accessible through a porthole in the shower stall. Harder to get my big hands in there as I had replaced this one a couple of years ago. I will keep after it one thing at a time until I find the problem.

[doxiemom11]

Air admittance valves can let grey tank odors into the rv and they smell just as bad as the black tank odors. There is usually one under each sink. Cheap and easy to replace - purchase at Lowe's type big box stores around $20. Screw old one out - new one in.

[CabinetmakerII]

lanerd wrote:

CabinetmakerII wrote:
Today I tried to Ops Check the Calgon and laundry detergent. Started by dumping the tanks both black and gray. Added the ingredients to the tanks with a few gallons of water. We drove about 100 miles toward Denali NP. When we stopped for a necessary break, the odor was present. RATS! We then continued toward Anchorage and stopped for the night at Willow AK. I figured the odor would be present. TO our surprise we were odor free. Yippee Skippy! We will try it again tomorrow and post the results. Hoping the KISS (Keep It Simple Stupid) method worked!

CM

That's good news CM. If you are traveling daily or more than a couple of times a week, I would only use the soap/calgon about once a week. The rest of the time, a few gallons of water in a freshly drained tank should suffice.

Just remember to use plenty of water when using the toilet and when draining/rinsing.

Have a great trip in Alaska.

Ron

We are in Homer Alaska and the problem continues. We are headed toward Anchorage tomorrow but it will take a few days to get there as there are a few places we missed on our way down the Kenai Peninsula. I believe there is a Camping World in Anchorage where I will pick up and install the Cyclone vent caps. I don't like being this tall let alone climbing up on the roof...

Thanks again for the help and advise.

Regards

CM

[lanerd]

CabinetmakerII wrote:
Today I tried to Ops Check the Calgon and laundry detergent. Started by dumping the tanks both black and gray. Added the ingredients to the tanks with a few gallons of water. We drove about 100 miles toward Denali NP. When we stopped for a necessary break, the odor was present. RATS! We then continued toward Anchorage and stopped for the night at Willow AK. I figured the odor would be present. TO our surprise we were odor free. Yippee Skippy! We will try it again tomorrow and post the results. Hoping the KISS (Keep It Simple Stupid) method worked!

CM

That's good news CM. If you are traveling daily or more than a couple of times a week, I would only use the soap/calgon about once a week. The rest of the time, a few gallons of water in a freshly drained tank should suffice.

Just remember to use plenty of water when using the toilet and when draining/rinsing.

Have a great trip in Alaska.

Ron

[randallb]

I experienced a holding tank odor occasionally when parked and sometimes when we would stop for lunch. I guessed that sometimes depending on wind direction the tanks pressurized slightly. I installed a pair of the pivoting Cyclone Vents and the problem went away. They point in to the wind which creates low pressure on the back side to draw the odors out. I will eventually put a set on our new 15RB hybrid weekender.

[Sam_Spade]

Now that you have the ingredients on hand you probably should stick with them......at least until they run out.

I like "Chlorox Cleaner with Bleach" for most wet cleaning tasks in my RV, including putting it in the mostly empty tanks when not in use. About half a cup with a couple of gallons of water. Works better if you have some road time before actually parking.

[CabinetmakerII]

Today I tried to Ops Check the Calgon and laundry detergent. Started by dumping the tanks both black and gray. Added the ingredients to the tanks with a few gallons of water. We drove about 100 miles toward Denali NP. When we stopped for a necessary break, the odor was present. RATS! We then continued toward Anchorage and stopped for the night at Willow AK. I figured the odor would be present. TO our surprise we were odor free. Yippee Skippy! We will try it again tomorrow and post the results. Hoping the KISS (Keep It Simple Stupid) method worked!

CM

[PUCampin]

We have this problem especially if we go over a couple particularly good bumps during the drive. The water will slosh out of the traps and on down the drain leaving a air gap for gasses to enter the trailer. When we stop and it is bad, I run the water a couple seconds at each sink / shower to refill the traps, open a window and turn on the fantastic fan in the bathroom. Problem resolved in about 60 seconds. You can't just stopper the shower, all the sinks have traps too.

[SoundGuy]

TechWriter wrote:
If you're going to dump chemicals down your tank(s), just use bleach. Cheap & fast acting.

Unfortunately bleach doesn't contribute to "cleaning" the tank walls or helping to break down the contents, especially hardened pyramids that may have formed over time due to prior inadequate tank maintenance. Lots of water, using a tank wand down the toilet throat to flush the black tank, and tank chems designed for the purpose will. One obviously can't wand the grey tank but I've found that using a GW tank treatment such as Walex Elemonate does help a lot. :B

[TechWriter]

SoundGuy wrote:

JD and Beastlet wrote:
We had the same problem and it was a surprise to use to learn after a couple of years that the smell was from the grey tank.

Grey water can smell remarkably bad. :E For two seasons now I've been using Walex Elemonate in the grey tank and never have any odour issues at all. :B

If you're going to dump chemicals down your tank(s), just use bleach. Cheap & fast acting.