Sewer Tank Odor in RV Bathroom and Cargo Area?

**MaryMac** · 07-24-2019, 08:51 PM

We also had the nasty smell. We replaced the AAV filters. The smell went away. Menards carries them also.

**Hhoelle54** · 07-24-2019, 09:18 PM

So let me ask you. Do you have a rotten egg smell when you run the water in the bathroom sink or any of the sinks.

We had the same issue after storing our GD Solitude 310GK for 8 months and then using it again. It took about a month for the oder to show up and then the tanks started smelling. We couldn't get rid of it.

So, Here is the solution I used. First I drained the black tank and flushed it until the water was clear. I then shut the valve added about 2 gallons of water and NO CHEMICALS AT ALL, THIS IS VERY IMPORTANT NOT TO ADD ANY CHEMICALS TO ANY TANKS DURING THIS PROCESS. I left the grey tanks 3/4 full. I then removed the whole house filter cartridge and filled the empty canister with swimming pool liquid chlorine reinstalling it without the cartridge. I then ran each faucet on cold water until only chlorine came out and shut them off. I flushed the toilet until the chlorine came out and did the same with the shower. I ran the hot water on one facet for 30 seconds to add some chlorine to the hot water tank. I then left this in the pipes for 8 hours. At that point I thoroughly flushed each faucet for 10 minutes clearing all the chlorine out. I ran each faucet on hot until the water was clear thereby flushing the hot water tank. I ran the toilet the same allowing the black tank to fill half way. You cannot have any chemical in the black tank at all during this process so you don't get a chemical reaction. THIS IS VERY IMPORTANT. The smell of chlorine was strong during the flush out process in the coach but dissipated within two days. I let the water sit in the tanks overnight disinfecting the tanks. I then drained all the tanks and flushed the black tank thoroughly getting all the chlorine out.

We then used the tanks as normal and have had no smell at all from any tank or faucet now for a month. As a note when we opened the bathroom sink faucet to clean the chlorine it came out black for the first 5 seconds. That was what was in the lines.

This was the suggestion of a friend who is a plumber. You also have to be careful to clean the chlorine off the sink drain chrome so as not to tarnish it after you fill the lines with chlorine.

As a side note all my tank sensors now work properly they did not prior to. Hope this helps you out.

**TheLexx** · 07-25-2019, 02:15 AM

This is is pretty much what I do except I just suction a mix of chlorine and water. Then I run the fixtures till I smell the strong chlorine smell. Shut it off and let the chlorine solution sit for 24 hrs. What this is doing is to kill the bacterial biofilm in the water lines. The next day I drain the system and refill it to flush everything out.

Originally Posted by Hhoelle54

So let me ask you. Do you have a rotten egg smell when you run the water in the bathroom sink or any of the sinks.

We had the same issue after storing our GD Solitude 310GK for 8 months and then using it again. It took about a month for the oder to show up and then the tanks started smelling. We couldn't get rid of it.

So, Here is the solution I used. First I drained the black tank and flushed it until the water was clear. I then shut the valve added about 2 gallons of water and NO CHEMICALS AT ALL, THIS IS VERY IMPORTANT NOT TO ADD ANY CHEMICALS TO ANY TANKS DURING THIS PROCESS. I left the grey tanks 3/4 full. I then removed the whole house filter cartridge and filled the empty canister with swimming pool liquid chlorine reinstalling it without the cartridge. I then ran each faucet on cold water until only chlorine came out and shut them off. I flushed the toilet until the chlorine came out and did the same with the shower. I ran the hot water on one facet for 30 seconds to add some chlorine to the hot water tank. I then left this in the pipes for 8 hours. At that point I thoroughly flushed each faucet for 10 minutes clearing all the chlorine out. I ran each faucet on hot until the water was clear thereby flushing the hot water tank. I ran the toilet the same allowing the black tank to fill half way. You cannot have any chemical in the black tank at all during this process so you don't get a chemical reaction. THIS IS VERY IMPORTANT. The smell of chlorine was strong during the flush out process in the coach but dissipated within two days. I let the water sit in the tanks overnight disinfecting the tanks. I then drained all the tanks and flushed the black tank thoroughly getting all the chlorine out.

We then used the tanks as normal and have had no smell at all from any tank or faucet now for a month. As a note when we opened the bathroom sink faucet to clean the chlorine it came out black for the first 5 seconds. That was what was in the lines.

This was the suggestion of a friend who is a plumber. You also have to be careful to clean the chlorine off the sink drain chrome so as not to tarnish it after you fill the lines with chlorine.

As a side note all my tank sensors now work properly they did not prior to. Hope this helps you out.

**Scott E.** · 07-26-2019, 04:39 PM

My wife noticed a stench around the sinks on our last trip a couple of weeks ago. For those of you who recommended the replacement Studor Redi-Vent, have you actually installed it? I removed the existing air valve in the bathroom and noticed that there was just enough room to unscrew and remove the device (it was up against the bottom of the sink counter). I took the existing device with me to Lowe's and the Studor valve is taller. Don't think this is going to work. Could cut out some pipe and use an adaptor, but how do you cut pipe that is located in the corner?

**Dick Noble** · 07-26-2019, 05:40 PM

Scott E -- I know that there is such a thing as a cable saw. I have used one as a Boy Scout. It is a length of cable with diamond pieces/dust imbedded in it with a ring on each end so that you can pull it back and forth with your fingers. You should be able to slip this behind the pipe and cut the pipe off. I bet you can find one in camping supplies at WallyWorld.

**J&G garage** · 07-27-2019, 07:12 AM

The bathroom plumbing for the AAV is ABS. I tried cutting it with a cable saw popular for use on PVS. No joy. Wouldn't cut the pipe. Multi Master type tool might work. I gave up. The few times the AAV has failed to seal (maybe twice) I have just removed it, flush it with water, dry and reinstall.

**kevinpo** · 07-27-2019, 04:29 PM

Would these (or something like it) work?:
https://www.acehardware.com/departme...hoCpMUQAvD_BwE

HTH,
Kevin

**Houndbb** · 07-28-2019, 04:03 AM

We haven’t gotten around to replacing the two AAVs in our trailer yet, but be aware that the Studor MINI vent is available on Amazon. You can buy ONE, sold and shipped by Amazon, for $23 and change. However, 2 and 3 packs are sold and shipped by a different seller and the price jumps considerably: 2/$100.01, 3/$180. Meanwhile, the local Home Depot has 10 in stock, at $24.87.

**Keebler** · 07-29-2019, 12:59 PM

Originally Posted by emessmer1

Well, you are right and wrong all at the same time. If you're using the formaldehyde based black tank treatments it'll likely harm nothing to have that detergent in there. However, if you're using an enzyme based treatment, the detergent will likely kill the bacteria that produce the enzymes that actually break down the TP and associated black matter. Same reason you shouldn't ever put bleach into a septic system. It's a living thing and if you kill the living part, you'll have hell to pay later. (A lot less hell in an RV... It'll just stink until you dump and clean, but for a septic system it can kill the entire system).

I definitely am NOT trying to create a living system in an RV holding tank (agree VERY different than a septic tank). My approach is to attempt to empty as much as possible from my tank. I use Bronopol free pods in an attempt to cleanse and deodorize versus an enzyme approach. Not knocking the enzyme approach, I just know what has worked for me.

Bottom line for me is that when we are talking about a holding tank that is totally emptied every few days, this has served me well.

**2goods** · 10-04-2019, 08:41 AM

I have a 2017 337 RLS that recently started to have the same problem. When the black tank gets near full sewer gas comes into the living quarters. It starts in the basement and comes into the bathroom through the vent behind the toilet and also comes into the kitchen through open cabinet drawers that are opposite the bathroom wall. That is because the backside of these drawers are openly exposed to the basement storage where the smell begins. The smell is not coming from the AAV valves under the sinks. The sewer pipe and vent pipe for the black water tank are properly fitted and glued into place. My only guess is that the vent pipe detached itself somehow from the roof vent itself and under certain conditions the gas is coming back down the wall behind the toilet (because that's where the pipe is routed up to vent) and filling the basement with gas. This seems to happen when the tank is near full and it's cooling off at night. Never happened in the first 2 years of ownership. May need to putt roof vent cap and run a camera down it.