Gray Tank Smell (Seriously annoying)

[Wulrich]

I love our travel trailer, but we have been having some serious issues with a very potent smell.

Issue: Every time we run the kitchen faucet we get a rotten egg smell out of both of our A/C units almost instantly. We’ve had the unit for about 3 months, and this has been going on for about 2 months.

Things I’ve tried:

1) Replaced the air admittance valves underneath both sinks.
2) Got on top of the unit to ensure the vents weren’t clogged, even ran water down them.
3) Cleaned gray tank, put tons of detergent, fragrances, and cleaning solutions in the gray tank to clean it.
4) Checked the anorod on the water heater
5) Keep the gray tank closed until ready to empty
6) Called the manufacture, they sent out a tech and were unable to find the problem. Have also called multiple service techs and no one seems to have heard of the issue.

Does anyone else have any other ideas? We are seriously bummed about it, my wife and kids hate it. We love the unit except for this issue. Any help is appreciated!

I have a 2022 Forest River Travel Trailer, Heritage Glen

[Dave_in_TN]

This product worked for me when we encountered grey tank odor issues. Of course if your problem isn't tank related this wouldn't help.

https://www.amazon.com/Camco-40597-Black-Cyclone-Plumbing/dp/B00SQ1K19A?th=1

[bukhrn]

You mentioned that you get the smell with the AC running, do you get the same smell from the sink area Without the AC on?

[Itinerant1]

If your black or grey roof vent pipes coming from the holding tanks aren't tall enough to protrude through the roof into the vent covers you might be getting some smell in between the roof and ceiling.

I had a stink occasionally and couldn't figure it out like you till I finally pulled the vents covers off, grey pipe was 1" shorter than the roof line. I added an adapter on problem solved.

[TechWriter]

agesilaus wrote:
Our fix: one small quart bottle of chlorine bleach in the tank.

x 2

[Lwiddis]

"Sanitize your whole water system with bleach. It may be microbes in your water lines."

Bleach is your friend. Use it liberally, let it sit in the fresh water system, run it into the waste tanks, let it sit and then rinse the fresh water system.

[agesilaus]

Our fix: one small quart bottle of chlorine bleach in the tank. Pour some down every drain. Leave in the tank plus some water, a quarter of more full, overnight. Drain. Good for a couple of months anyway.
I suspect bacterial film forms on the walls and that film is very tough to remove.
We have one of those directional vane caps that is supposed to turn the vent top away from the wind, did not seem to be effective. Noticed the smell increased when ac on, suspected ac inlet is ingesting air from the tank vent. But as pointed out above that is not the case.

[valhalla360]

The air/con doesn't pull air from outside to inside and should have no other connection to the plumbing system, so the rooftop vent is unlikely to be a factor.

The air/con circulates air being picked up from the main panel in the ceiling pumping it thru the vents. Best guess is the odor is being released from the sink area right below the air/con unit and it is pulling that smelly air into the system to distribute it.

The air/con is most likely a symptom but not a cause.

Try using the faucet to put water into a bowl without any going down the drain. Is there a smell?
- If yes, it's likely in the fresh water supply system.

If not, dump the bowl down the sink. If that causes the smell, it's likely in the drain system.

[MitchF150]

Have your tried running the sink faucets into a tub only? This would eliminate the holding tank in the equation. Then, if you smell the same thing, then it's your water source.. If you don't smell anything, then it's the holding tank.

Not sure what the solution would be for either issue, but at least it might help narrow down the guessing?

Good luck! Mitch

[2oldman]

Wulrich wrote:

2oldman wrote:
Is you kitchen in a slide?

It is not in a slide, it’s in the center

Okay, mine is, and what happened to me is after 20 years of sliding, the flexible tubing carrying sink water came loose and allowed water to drain inside. I only found it when water was dripping onto the ground through the frame.

[2112]

Wulrich wrote:

2oldman wrote:
Is you kitchen in a slide?

It is not in a slide, it’s in the center

I'm thinking the AC is above the sink and the AC is sucking the water smell into the ductwork

[2112]

Correct.

Are you experiencing this at the same camp ground or area?

Next time you are experiencing the smell, go outside, disconnect the water hose from the water source hose bib and see if you smell anything from the source.

Sanitize your whole water system with bleach. It may be microbes in your water lines.

I filled my fresh tank with campground water that was supplied from a West Texas water well. After a few days it smelled horrible. Both hot and cold. I had to overdose my water system with bleach to clean it out.

[Wulrich]

2oldman wrote:
Is you kitchen in a slide?

It is not in a slide, it’s in the center

[Wulrich]

2112 wrote:
It could be the water heater anode reacting to the water. This has happened to us a few times

***Link Removed***

Try a zinc rod
***Link Removed***

We get the smell whether we are running cold or hot water. You would think if that was an issue, you would only get that smell with hot water, correct?

[Wulrich]

Larry cad - the A/C draws from the inside, not the outside. The smell seems to be persistent if I leave the gray tank open.

Lantley- I’ve checked all the caps at the top, seem to be functioning properly.

[2oldman]

Is you kitchen in a slide?