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

[SoundGuy]

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

[JD_and_Beastlet]

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. RV showers have small P-traps that are prone to drying out. We starting putting a plug in there when we weren't using it and the problem went away.

[CabinetmakerII]

lanerd wrote:
Before you travel, try putting a cup of laundry detergent (liquid) and a cap full of Calgon water softener along with about 5 gallons of fresh water in both black and gray tanks. Sloshing around while you travel will clean out the insides of the tanks and once you arrive at your destination, drain both and rinse out the black. I bet your odor problems will disappear.

Give it a shot.

Ron

Thanks everyone for your input! We already bought the Calgon as we had used that before a few years ago. Had not heard about the laundry detergent so will try this method first. If this does not help I will move on to the other suggestions one at a time with the simple ones first. We are relocating from Fairbanks to Anchorage tomorrow. We will see if the Calgon does the trick.

CM

[wingsfan20]

Check that you have water in all sink traps not just toilet. Bathroom drain may go to black tamk. On the road water may be emptied from trap due to rough roads.

[RoyB]

I had something similar leaving my bathroom vent opened a tad when driving. The air flow sucked up the fumes through the pot I guess as we smelled sewer as well. Kept the bathroom vent closed and didn't have amy more problems...

Roy Ken

[mvpmich]

Try this. It solved the problem for me.

http://www.camco.net/product/cyclone-plumbing-vent-10548/

[lanerd]

Before you travel, try putting a cup of laundry detergent (liquid) and a cap full of Calgon water softener along with about 5 gallons of fresh water in both black and gray tanks. Sloshing around while you travel will clean out the insides of the tanks and once you arrive at your destination, drain both and rinse out the black. I bet your odor problems will disappear.

Give it a shot.

Ron

[Sam_Spade]

CabinetmakerII wrote:
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

Check them before you give up.
Sometimes insects can close them off with nests.

And check under/around other plumbing too.
What you are smelling could be mold somewhere else.....or a dead rodent. Take out drawers and look under cabinets.
Inspect little used storage areas.

[midnightsadie]

I had this problem once, looked every where, out of being desperate I changed out the seal kit in the toilet ,problem gone. bought a complete toilet rebuild kit sat down on the grass and it took about a hour.