Septic odor 310-GK bathroom--NOT AAV

[acadiaforever]

We're getting an intermittent strong septic odor in the bathroom when we shower. It is not the Air Admittance Valve. We've already replaced that and the air under the sink smells fine.

We replaced the dinky fan that comes with the rig with a second Fantastic Vent, so we're drawing significantly more air out the vent--but even running it at 50% we still get the smell. I've been unable to localize the odor. I've checked (sniffed) the ceiling air conditioning vent, the heater vent, and the shower drain (the 310-GK uses a regular P-trap, not the Hepvo "duck bill" trap). The water block is in place in the commode, so it isn't coming in through there.

Even though the I couldn't smell any at the floor, does this commode use a standard wax ring, or a neoprene gasket to join to the drain pipe? In other words, if I pull it to check for a possible leak there, is it easy to replace? (I hate cleaning up wax ring mess, but I can do it if needed.)

I'm out of ideas. Has anyone else experienced this when it is not the AAV?

Thanks for any suggestions.

[howson]

We're getting an intermittent strong septic odor in the bathroom when we shower. It is not the Air Admittance Valve. We've already replaced that and the air under the sink smells fine.

We replaced the dinky fan that comes with the rig with a second Fantastic Vent, so we're drawing significantly more air out the vent--but even running it at 50% we still get the smell. I've been unable to localize the odor. I've checked (sniffed) the ceiling air conditioning vent, the heater vent, and the shower drain (the 310-GK uses a regular P-trap, not the Hepvo "duck bill" trap). The water block is in place in the commode, so it isn't coming in through there.

Even though the I couldn't smell any at the floor, does this commode use a standard wax ring, or a neoprene gasket to join to the drain pipe? In other words, if I pull it to check for a possible leak there, is it easy to replace? (I hate cleaning up wax ring mess, but I can do it if needed.)

I'm out of ideas. Has anyone else experienced this when it is not the AAV?

Thanks for any suggestions.

Check out this thread, especially post #8 : https://www.mygrandrv.com/fo...4361#post64361

[FT4NOW]

No wax ring, it's a rubber based gasket for the floor to toilet connection. Is it more of a septic smell or rotten eggs? Might be a bit of a stretch, but have you checked the water level in your battery?

Sent from my SM-G950U using Tapatalk

[acadiaforever]

Thanks to you both. Definitely septic. I hadn't thought about the vacuum breaker and didn't know where it is; I'll check that out this afternoon!

[Cate&Rob]

Hi Al,

Have you tried running the shower with the exhaust fan off and the vent closed . . . to see if this makes any difference. We had a problem like this early on and it turned out to be the exhaust drawing air up from the basement. The smell was from a tank vent connection that had not been properly glued. Seems the water going into the tank combined with the slight vacuum from the exhaust made this a preferred path to venting up the stack. A smear of silicone around the vent joint solved the problem.

Rob

[CoChris]

Thanks to you both. Definitely septic. I hadn't thought about the vacuum breaker and didn't know where it is; I'll check that out this afternoon!

If you mean the vacuum breaker for the black tank flush, it is in the wall between the shower and the pantry on the 310GK. You can access it by removing a panel in the back of the pantry. One section of the back wall between shelve is screwed in place. The vacuum breaker will be around (should be above) that area.

But I am confused. You say you get a septic smell when you shower. The shower should drain into the front grey tank and not be connected to the black (septic) tank.

Another thought is the bathroom heat vent (beside toilet on side of shower wall) comes straight from behind the basement wall, right over the tanks. If the vent fan is pulling a vacuum in the bathroom and there is sewer gas present behind the basement wall and the heat vent (or any part of the bathroom wall) is not well sealed, it could be pulling sewer gas into the bathroom. Just a wild thought.

Good luck in tracking down the problem. Let us know what you find.

Chris

[andrewssteve]

Thanks to you both. Definitely septic. I hadn't thought about the vacuum breaker and didn't know where it is; I'll check that out this afternoon!

We've got a 310 GK as well. This summer, on just a few occasions, we noticed a septic smell when we opened the entry door to the RV after pulling into the next camp site. This even occurred in the mountains when it was cool, not hot. Just guessing, but I think the problem only occurred when we traveled with non-empty tanks. (Never had any septic smell in my last RV.)

We had the dealer check it out (tanks were empty!), and the tech didn't find a problem.

Please post again when you define the problem. Thanks.

-Steve

[TucsonJim]

Sometimes, a vent pipe can fail and let odors into the coach. Take a look at this break from my 2014 337RLS. The break was located behind the electrical breaker panel. We had an odor around the bathroom for over a year before I found it. Sometimes these odors can be hard to diagnose.



Jim

[RVRunners]

Sometimes, a vent pipe can fail and let odors into the coach. Take a look at this break from my 2014 337RLS. The break was located behind the electrical breaker panel. We had an odor around the bathroom for over a year before I found it. Sometimes these odors can be hard to diagnose.



Jim

Yes definitely check the vent pipe on the front grey tank. There is a chance this is your issue. I know someone previously mentioned that the shower is going to the front grey tank and this is correct, however, grey tank odors are terrible as well so it doesn’t have to be coming from the black tank to be unpleasantly fragrant. Good luck!

[JCRICHRI]

Hello all,
My 3rd trip on a solitude 3740 . Almost the same Problem. The issue is a sewer smell coming from the shower drain. Only when you first let the water run in the shower. It occurs for the first minute or so then stops. Doesn’t make a difference with fan on or off, gray tank closed or not. The smell never comes from any other drain. I pulled the AAV under bath sink and inspected. It looked like the spring loaded flap moved well. I called grand design and they didn’t offer much help. They suggested I look for the blank tank vacuum value behind the shower faucet. I’m not sure how that could create the issue. They also asked if I had 2 pipes for vents stacks or 1. I think I have 2 . One is black on the roof and another has a white cap in the same area. Anyone ideas. I haven’t checked out the black vacuum value yet because I don’t think the black tank issue would cause this.

Any help or ideas. Thank you all.