Sewer smell

[Camper1965]

We bought our 2021 3761FL 5th wheel in April 2021. Camped in it in May for 3 days. Had all sorts of issues-leaking roof, air not cooling, refrigerator not cooling, master toilet had no flapper so open into lines, invertor hooked up backwards and couple other issues. Took to dealer and dropped off on way home. Kept mths and when picked up was told issues fixed. A/C wasn't fixed so when ask they said that it was normal for it not to cool a camper that size. Would get up to 85 with air blowing full blast. But here is my main problem at this point. The camper has been camped in on it maiden trip and stored in a warehouse since because it literally stinks so bad that you can't stay in it. Original dealer kept cancelling appts to check it so finally took to a satellite lot of theirs and they have had it since 1st of Jan. Called today and was told to come get it they have no idea of how to fix it. The sewer smell is so bad it was in my husband's hunting clothes that were in there and I had to wash them before he could even wear them. I can find no help with this issue.

[Carl n Susan]

Bummer on all your issues.

How many ACs do you have? If only one, it is true that you will have a hard time keeping the RV cool in high temps/humidity.
You wrote the RV was only used once 2 years ago. But there remain a horrible sewer smell. Was the black tank ever dumped and flushed? Even if not evaporation should have dried up everything by now. Where is the smell coming from? Bathroom, passthru, under the coroplast, dead animal in the ceiling or under floor or ?
It sounds unusual that the dealer agrees there is a sewer smell but they have no idea to on how to fix it.

[Camper1965]

It has two a/c units and the tanks were dumped at end of trip. We grew up camping and have not been without a camper ourselves since we've been married. We are at a loss with this issue. I have opened it up and let it air out thinking it may have been with the original issue of the 1st toilet not having its flapper. But it is still there. When you open the underbelly storage up it will knock you down. You can actually smell it in the warehouse when you walk around the camper. The service agrees there is a problem but says they have no answers. I spoke with another service dept and he said they had had another one come in before with the same issue and they couldn't find it either on it.

[AZ Traveler]

Might be a black tank leak. Do you see any signs of leaks.

I would flush the tanks well with a good detergent and lots of water. Open it all up and let it air out well with fans blowing. I assume the flapper valve is the valve in the toilet bowl.

Another option for help might be one of the mold/water damage restoration companies.

[Mikendebbie]

You have a sizable investment in the RV.
I would find a certified RV inspector in your area to come look at every system, the roof, the air conditioners, the furnace, the gray and black tanks - everything. Make sure the guy you choose will provide a itemized list of problems with suggested fixes. Website - NRVIA.org

He can help you plan the next step - whether you go to Keystone or another dealer. Maybe some of these issues can be fixed by you.

AND come back here and post the results of the inspection and let forum members advise and help you. Maybe it’s not yet time to give up!

[Foldbak]

It wouldn't be unusual for an in wall vent leak.....I've seen several.

[DutchmenSport]

You have a 3761FL 5th wheel. It has the front living room and the rear bath across the entire back end. You also have that massive storage in the rear drop frame under the rear bathroom and rear bed room. Inside that storage area, the pipes are covered, then go through the floor of the storage area and into the holding tanks. The holding tanks cannot be seen because of the underbelly cover.

Has anyone actually removed those covers around the pipe work? Has anyone actually opened up the underbelly to see if something is dripping under it. Or maybe a small animal crawled in that cavity and died?

I had problems with my truck last year. The wheels were making a horrible squeeking sound, but it only occurred under very specific conditions. We were 600 miles from home and decided to take the truck into a GM dealership repair shop. They looked at it while I waited 3 hours. They came back and told me they could not find anything. I told them I wanted a complete brake brake job on it, something was going on. They gave me all kinds of songs and dances. I gave up and eventually towed 600 miles back home.

The first thing I did was get with my home GM dealership repair shop and (in time), they agreed to pull the wheels, check everything. It turned out my front brakes had only 1% usage left, and the rear brakes had 3% usage left. I had 2 messed up calipers and the total bill was around $4000 for all the repairs, brakes, pads, calipers, everything. It was a mess.

Those buzzards at the first shop just blew me off. That was quite obvious (after the fact). They just did not want to deal with me or my truck (probably because I was not a local good-old-boy). I know they did absolutely nothing, except, maybe.... drove it around their parking lot and maybe around the building, came back and said they couldn't find anything wrong. Yea!

So you know ... I think your repair shop is full of "it". There is a problem. Go somewhere else if you have to and stop listening to them. But, since you are past warranty now anyway, there is no reason why you can't tear into the innards of your camper yourself. You've got nothing to looses, except sitting at home brewing about your loss when you could be out camping somewhere.

[firestation12]

You stated the tanks were dumped at the end of the season but didn’t say if they were partially filled and treated. If not, when the toilet flush seal dried out, an empty black tank could easily migrate its smell into the camper. I’d start by mostly filling the black tank and simultaneously adding chemicals during fill to mix them. Some fabric softener could also be added. The grey tank I’d also do the same adding Dawn dish soap (maybe a cup). Lysol could be used on fabrics and lastly, open windows and let rooms vent for several days. You will soon know if this is the right course if the problem is abating. Best of luck and leave a follow up post for us all.

[scattershot]

Check your water heater.My son in law had the same problem, and it turned out to be bacteria in the hot water tank. A capful of Clorox and flushing the tank did the trick. Good luck! Please keep us posted.

[432bartman]

Does your state have any kind of lemon-law? It sounds like you have a whole bunch of issues, which should not be the case with a brand new rig. I feel horrible you're going through this. I hope you are able to resolve everything.

[LeftOverParts]

Although out of warranty, since the dealer didn’t fix the original issues and then blew you off, maybe it’s worth contacting Keystone. Hopefully you have docs and dates to support your experience. The contact number can be found in the link attached.

https://www.keystonerv.com/customer-service

[Jay & Bobbie]

I agree with Mikendebbie. It will likely cost a hot nickle, but a certified rv inspector is trained and hopefully has the experience to diagnose issues like this. You will also get a report that is indisputable, that you can take to the dealer. Many inspectors are also certified technicians. He/she may even be able to make necessary repairs.
The vent pipe in the wall is a possibility. I have seen homeowners drill holes in plumbing vent pipes while hanging mirrors.
Would also like to know what the issue turns out to be.

[rohrmann]

Besides a toilet flush seal leaking, depending on whether you have Hepvo devices or actual P traps under the sinks and shower, the P traps may have dried out and the Hepvo devices sometimes get crud in them which will not allow them to seal properly. That may be a source of the odor.

[Ralph0808]

I would look for a vent in the walls that may have a flap open or as pointed out the water heater if a suburban brand the anode rod may need to be aluminum instead of magnesium it can cause very bad odors. But sewer odors is a vent open in the basement or in the walls somewhere. Maybe get a inspection camera to check the vent stacks.

[ingalmi]

Just to add, it’s quite possible that the black tank vent is not connected at the top of the tank. How many black tanks does it have? Sitting in storage that long without water and treatment along with a vent line not connected would be smelly!! Drop the Coroplast in the area of the black tank and check it.

[Trudy]

Take it back to factory if no one can find the problem. You have been without it this long… what does another couple months hurt!

[jackt]

We had a sewer smell every time we used the bathroom sink. Our camper originally had the washer/dryer in it but its since been removed and shelves put in its place. What we found was that the water lines going to the washer/dryer area needed to be flushed. Once that was done, the sewer smell went away.

[dfb]

Have the dealer first fix the toilet. Smell will come up without the seal flap in it. Next, have the dealer remove the underbelly and start inspecting. Have the black tank flushed well the fill it without emptying it. If you have a black tank leak it will show when the tank is filled to the bottom of the toilet. If that all check out well, then a vent tube is not connected or cracked. But the bottom must come off..

[AZ Traveler]

Appears the OP has ghosted us?

[Daryles]

I saw this on another website. The owner had water running out from under the coroplast. They took down the basement walls and found the vent pipe had not been glued into the tank.