Sewer Tank Odor in RV Bathroom and Cargo Area?

[terryannbautz]

We have owned our 2016 Reflections fifth wheel 337RLS for about 18 months now - we bought it gently used. My question is regarding getting rid of the sewer odor or is this just something we have to deal with? The sensors for the black, sewer tank have never worked, and now the two gray tanks also do not show empty when dumped (my husband says this is common with RV tanks.) We know it is time to dump because of the odor, which can be smelled from inside the bathroom, kitchen area and also in the cargo area below the bedroom, which is accessed from the outside. After dumping the black tank, I have the hose hooked up with valve open and rinse out the black tank until it runs clear, then dump the two gray tanks. I then put 1-2 Camco MEGA All-in-One sewer Tank Treatment in the toilet and flush down with water. It still smells after I do this, but usually after about 6 hours or so the smell goes away. I just wonder if this is normal or if I should be doing something different? I wonder if having the tanks professionally cleaned out would help...does that help the sensors to work again? I also saw something about a formula using Calgon Water Softener and another product to add to the tanks to clean them...but can't find what the exact formula is...anyone tried that and can give me the correct formula if so? Thanks for your comments!

[gbkims]

Could check the air admittance valve under the sink. See if the shower has a P trap.
https://www.mygrandrv.com/forum/show...f-sewer-inside
https://www.mygrandrv.com/forum/show...throom-cabinet

[terryannbautz]

Thank you for your comments. Will check p traps, but the smell DOES go away after about 6 hours of emptying the tank. It's just smelly once the tank starts filling up.

[Keebler]

As Gene mentioned above, check the air admittance valve, pretty cheap and simple fix.

I had the strong rotten egg smell; changing this out did the trick. Mine was located in the bathroom cabinet under the sink.

[Steven@147]

We have owned our 2016 Reflections fifth wheel 337RLS for about 18 months now - we bought it gently used. My question is regarding getting rid of the sewer odor or is this just something we have to deal with? The sensors for the black, sewer tank have never worked, and now the two gray tanks also do not show empty when dumped (my husband says this is common with RV tanks.) We know it is time to dump because of the odor, which can be smelled from inside the bathroom, kitchen area and also in the cargo area below the bedroom, which is accessed from the outside. After dumping the black tank, I have the hose hooked up with valve open and rinse out the black tank until it runs clear, then dump the two gray tanks. I then put 1-2 Camco MEGA All-in-One sewer Tank Treatment in the toilet and flush down with water. It still smells after I do this, but usually after about 6 hours or so the smell goes away. I just wonder if this is normal or if I should be doing something different? I wonder if having the tanks professionally cleaned out would help...does that help the sensors to work again? I also saw something about a formula using Calgon Water Softener and another product to add to the tanks to clean them...but can't find what the exact formula is...anyone tried that and can give me the correct formula if so? Thanks for your comments!

First thing I would do is replace the AAV (Air Admittance Valves) under the kitchen sink and under the bathroom sink. $20 each from Home Depot. The ones the manufacturers use are cheap and fail most often.
Yes the tank sensors are notoriously inaccurate but owners can be some of the cause. Example if your staying at a campground for a while with sewer hook up, its not a good idea to leave the black tank dump valve open all the time. This allows the liquid to run out of the tank and solids tend to stay in the tank and pile up with paper covers the sensors. Leave the blank tank dump valve closed until tank is fairly full, then dump and rinse. A good flushing of the black tank and maybe even use one of those cleaning wands that you stick down the toilet hole might help to flush the tank and get the sensors working somewhat again.
Same with the kitchen sink grey water tank, don't allow solid material to drain into the tank and pile up, and use good dish washing soap that doesn't leave a film to coat the sensors. Kind of like the old Ivory soap commercials that tout not leaving a film behind.There is really no access to the grey tanks to flush them out.
It also might be a good idea to gain access to the individual tank plumbing lines behind the storage compartment wall just to check to make sure none of them are leaking or cracked.

[Keebler]

I also saw something about a formula using Calgon Water Softener and another product to add to the tanks to clean them...but can't find what the exact formula is...anyone tried that and can give me the correct formula if so? Thanks for your comments!

Regarding the formula for Calgon, there are a number of different opinions out there on a formula. Here is one: https://sites.google.com/site/cbruni/

I have never tried it, but I am an advocate of pumping in 5 gallons of clean water after I do my thorough black tank flush. Once I am cleaned, I simply close the valve and let the black tank flush valve run a bit. I used to be more precise and measure how much water I was pumping in. I don't take the time to measure anymore. I used this: https://www.amazon.com/Rainwave-RW-9...s%2C137&sr=8-3

If I am at a full hookup and have time, I will squirt (no measure) some dawn into the toilet before adding the ~ five gallons of water. I feel like this water and detergent sloshing around until the next trip can't hurt anything.

[Walkdog]

I pull a 2016 337rls and when dumping black I always back flush till its totally clear. I usually let my back flush run for around 10 min and then close the valve and fill tank a couple times flushing when almost full. Usually always total clear water running out. Be careful on flush/filling tank as not to forget about it. I did, small flood come up out of my commode and I was in fast gear turning water off, luckily it was easy cleanup and clear water running by then.

Traveling is key to flushing or really cleaning your other tanks as in some water in those tanks with a cleaner or water softer sloshing around while traveling does a real good job.

[Steve7]

Thank you for your comments. Will check p traps, but the smell DOES go away after about 6 hours of emptying the tank. It's just smelly once the tank starts filling up.

Since you also empty your grey tanks every time you dump your black tank, this could explain why the smell dissipates after several hours. Like others have said, change out the aav, and if you can get a wand down your toilet. They clean really well. I use it a couple times a year. The toilet pipe needs to be straight down though to use a wand. Some toilets have angled pipes.

[Houndbb]

We have owned our 2016 Reflections fifth wheel 337RLS for about 18 months now - we bought it gently used. My question is regarding getting rid of the sewer odor or is this just something we have to deal with? The sensors for the black, sewer tank have never worked, and now the two gray tanks also do not show empty when dumped (my husband says this is common with RV tanks.) We know it is time to dump because of the odor, which can be smelled from inside the bathroom, kitchen area and also in the cargo area below the bedroom, which is accessed from the outside. After dumping the black tank, I have the hose hooked up with valve open and rinse out the black tank until it runs clear, then dump the two gray tanks. I then put 1-2 Camco MEGA All-in-One sewer Tank Treatment in the toilet and flush down with water. It still smells after I do this, but usually after about 6 hours or so the smell goes away. I just wonder if this is normal or if I should be doing something different? I wonder if having the tanks professionally cleaned out would help...does that help the sensors to work again? I also saw something about a formula using Calgon Water Softener and another product to add to the tanks to clean them...but can't find what the exact formula is...anyone tried that and can give me the correct formula if so? Thanks for your comments!

Terry, We have this problem, mostly at the beginning of the season. All of the advice above should help you out. We also try to use the “Geo Method” for cleaning, odor, and sanitation, throughout the season (for us, April-October; yours is probably longer). Anytime we travel, we try to have 5-10 gallons of water in the black tank, along with a cup of liquid laundry detergent, liquid Calgon water softener, a bottle of Camco TST Max (available in multi-packs at Walmart). We also add half a bottle of Thetford Drain Valve Lube at the beginning and end of the season. The reason for this, and only using liquids is because early on, when the trailer was new, we had problems opening/closing the gate valves. One was so seized, it needed to be replaced and when we asked how to avoid the problem, the tech who worked on it told us never to use anything in powder form in the tanks.

Also, we use the TST in both of our grey tanks as well. Spit and toothpaste and last night’s dinner remnants can begin to smell pretty bad, sitting around for awhile (as evidenced when cleaning the bathroom and kitchen P-traps at home).
N

[Dick Noble]

In 20 years of RVing I've tried everything. Only thing I think that works (some) is lots and lots of water. I do use Calgon with dishwasher liquid (low foam)and lots of water when we take off in both black and grey tanks. We are lucky in that we have full hook-ups at home so we can drain all tanks and let then dry well. Still have problems with the sensors. We do have and use a back flush attachment and black tank flush built in.