How to fix bad smell in trailer | Dometic 300 issue

[@larrylindaorrick9148]

Just got done fixing our 300 toilet. A couple of suggestions. First, I used 5200 marine caulk which is used for thru hull fittings on boats… it’s “permanent” and doesn’t come loose. Second, you should lightly sand the surfaces you want to mate to give the caulking more grip. It’s hard to bond the ultra smooth surface of the plastic. And third, you should remove all the silicone grease that they slather everything with with a solvent or the caulking won’t stick well. Good luck with your repairs and thanks for the great video to get everyone started.

[@thericardocartagena]

This is great feedback, thank you. I will definitely try the sanding and marine caulk in the future.

[@Wack-EJ]

wouldnt the caulk interfere with the big black rubber seal most people end up replacing? otherwise could you get it out later on if needing to replace it?

[@krisg3984]

About the 5200 marine sealant-- stipulate the FC ( fast curing ) type. Otherwise it will take a week before it cures

[@MalcolmStranathan]

I just wanna say. Thank you. We have flushed and cleaned the black tank saw nothing but clean water and it was rank in the toilet. Finally thought I'd check and see if anyone else had this problem and I was surprised to see the number of complaints. We were way out of warranty so the only fix was yours. And I can say it was easy. Not pleasant by any stretch (stench) or means. It is fixed and I will report back how this performs. Thank you Ricardo! Much obliged.

[@ronewen5034]

Great Video, Just now got off the phone with Dometic. They are replacing my 1.5 year old 300 model with a new modified 300 model no questions asked. The diffence between models is the new unit has 2 gaskets instead of 1. The customer experience was great.

[@firesideweekenders]

Thank you. That is great to know. Thank you for the feedback and glad to hear you are getting a replacement.

[@toneilmt]

Word of caution to users of a "replacement" 300 - we had the same experience with a newly purchased 2019 toilet - worked great the first year, then experienced the internal leaking and odor. After getting a warranty replacement in 2020, it worked for one trip, then same failure. I took it apart and it is the "new" two-seal model - which failed just the same. I'm now replacing with the 310 model.

[@grcooley]

Well done, a great and useful How To for those of us with this problem. Rather have a video like this than deal with Manufacturer excuses. Thanks so much

[@firesideweekenders]

Thank you. Hopefully it helps.

[@rossklock2505]

Just want to thank you for posting an excellent instructional video. You gave me all the information I needed to finally find the cause and deal the odour problem that had become progressively worse during the first year since purchasing our new winnebago trailer. Using your step by step dismantling procedure I discovered the stinking mess that had accumulated inside the internal bowl cavity and was able to clean and properly reseal the unit. Problem solved but it's a shame that Dometic doesn't take more responsibility for this product. At the very least they should be issuing a tech note to buyers indicating the problem, post the appropriate repair and possibly offer a new seal kit to eliminate the problem.

[@firesideweekenders]

Thank you very much. We are very happy to hear our video helped you find the cause of your problem.

[@renewinnik568]

I did the exact same. I have a 2014 Bullet 310 BHS and it has had the problem since day one. When I pulled the bowl apart I was both sad and very happy. Sad that I had to pull it apart to begin with and that Dometic and Keystone did not suggest this and happy because when I pulled it apart, I found the dried mess thus letting me know I am on the right track. I would post a picture but who would like to see that. Thanks again for putting this together. Hopefully this will be smell-less season for the first time since I bought the camper. Thanks Again!!

[@graysonanddad4938]

Did you notice your smell in and around your toilet? I'm dealing with a bad sewage smell but it doesn't seem to be coming from the toilet, rather it's stronger by the exterior wall. I will perform this fix regardless as it seems a good idea for preventative reasons, just curious about what others have experienced. Thanks in advance!

[@msla5274]

Thank you so much for this video! I have a 2008 Four Winds Chateau Sport that I have renovated. Went camping last week and noticed a foul odor in the lavatory and eventually it became a stench! There are many KZbin videos on how to fix the problem and yours is, by far, the best one. I cleaned up the Dometic 300 yesterday, I was dreading the process, although it wasn't too bad. I did have to stop in the middle of things a run to Home Depot to get a long flat head screwdriver, a shorter just won't work. I hope the fix lasts, otherwise, I will get the Thetford commode! 🚽🤮

[@mickav4729]

Any update?

[@msla5274]

@@mickav4729 Had the chance to go camping this past weekend, had not been since I repaired the toilet. Dumped my tanks and again, there is a bit of an odor that is not quite as bad as the previous stench! I am going to check out the toilet again and if there is the same problem, I am going to replace with the Thetford commode.

[@flatlander6928]

Great video, very informative. So you pay premium money for an RV rig, and they know they have issues with their product that can damage that asset, not to mention the health hazard. Mine is a Flagstaff microlite, 2017. It's been relatively reliable, and I love the outdoor kitchen, but it's been one minor issue after the other, now THA STANK. Was trying everything to get rid of it, and find these videos describing my exact issue. I just got back from ten days in the N.C. mountains, living with this persistent stank the whole time. This is insane, paying money to spend more money on a product that is totally inferior, THE WHOLE RV IS JUNK. I'm fixing my john and selling my rig as soon as possible. I'm thru with camping for good in an RV. One important piece of advice you tube land, if your not mechanically inclined, don't buy an RV, it will be in the shop longer than at home. Good luck to all of you happy campers and God Bless.

[@roberttaylor8261]

Very nice informative video! Hope to do this this weekend! I’m sure this is my problem as the Sewer smell seams to be coming from the back opening of the toilet! I have watched other videos where people removed the Dometic 300 Toilet to replace it an dump a qaurt of nasty urine out from back of toilet.

[@StoneMountain66]

Thanks for posting this. You prepared me for the nasty mess to clean and trust it will be a long term fix.

[@cherinoble3289]

Great video. My 3 year old Dometic 300 just started smelling and I didn’t understand where the issue was/ is. Now I do and as soon as I get home from current trip I plan to do the repair.

[@firesideweekenders]

I am glad we were able to help you figure out the problem. Thanks for watching.

[@angeladealbuquerque3262]

We are currently on a long trip after having bought a used 2020 Geo Pro Trailer. Since we’ve been on the road, we have been having urine smell, which is getting worse. Your video was eye-opening so we just used a mirror to look into the back of the Dometic 300 toilet and lo and behold, urine in the hold! Unreal! Why Dometic doesn’t take this model off the market or recall them and offer a fix is beyond me. This RV and trailer industry is so bad with so many cheaply made products thrown into these units as well as being snotty made. Owners spend so much time fixing, upgrading, renovating even new units. I would tell anyone who wants to travel this way, to rethink. This industry is an embarrassing mess.

[@firesideweekenders]

Oh nooo. At least you found the smell. Hopefully you fill resolve the problem soon. Safe travels.

[@ronmroczenski3562]

Very good question for Dometic. Not buying another Dometic

[@dougclark6696]

Thanks for sharing. Our nearly 3-year old Dometic 300 had bad smell all weekend. Smell was different (worse) than black tank odor! Removed toilet and saw the nasty water caught inside, just like you described. With your detailed video, I was able to get it completely apart and I got it nice and clean inside. Reassembled with generous amount of silicone sealant at the areas you described. Hoping for the best!

[@firesideweekenders]

That is great. I am glad the video helped.

[@RussC123]

The 3-ish year mark is exactly when this happened to me (just this past weekend, actually). Has this fix worked long term for you?

[@tom-ss2mn]

I have a 2019 bumper pull. Thedford toilet. Smells like septic around and behind commode. I wonder if this could be the same situation as dometic 300. Ive searched but seen no talk about this problem in thedfords tho

[@kenanmorg4677]

Thanks so much for this video....although my toilet leak was from the water supply inlet, it was good to learn how to disassemble the toilet since I have the exact same john. Actually, I have the exact same camper as you so I was able to upgrade my air conditioner to the bluetooth panel and also watched your vid about installing a backup camera which was helpful. Thanks again.

[@firesideweekenders]

You are welcome. Thank you for watching and I am glad the video helped.

[@johnn753]

Excellent video. 4 year old unit. Started having smell issue this trip. Tried everything. Saw your video. Pulled toilet and there was toilet water inside just like you stated. Siliconed today. Hope it works. Thanks for your useful video. Cheers

[@firesideweekenders]

Glad it helped.

[@renewinnik568]

Thank you! Called dometic and keystone and no luck. I have a 2014 bullet 310 bhs . It has happened since day one. I followed your video and this is the first year no smell. Inside was really nasty .

[@firesideweekenders]

Glad the video helped. Hopefully it wasn’t too messy lol.

[@cathiekittleson4848]

Thank you for your informative video. We had an awful smell that we couldn’t get rid of no matter the amt of chemicals we added to the black tank. Well, it wasn’t the tank! The Dometic toilet seal was not working and allowed black water to FILL the molded bowl. It had almost a gallon of liquid in there. Again, thank you for showing us how easy it is to stop this. Our camper is now winterized so we will have to wait and see if it works until next spring.

[@firesideweekenders]

You are welcome. Glad we were able to help. Thank you for watching.

[@sueharris8685]

Just saw your video. We have a 2020 Rockwood Minilite and we are having the same issue that is smells. Everytime we flush the toilet and come back, there is a yellow liquid in the toilet, just couldn;t figure it out. We have tried everything and now after seeing this video i think we found the problem. I am going to call Dometic and hopefully they will send me a new toilet, thanks for the great video.

[@m1chance]

Thanks for this video, I came across a link for it while shopping for a replacement for my dometic 300. I will definitely try this before spending any money

[@Weezieweeks]

Awesome timing on this video! We just got home from Flagstaff and knew there was a problem. We are hoping this method will work until we can install a new one, whether the 310 or the 320 as we are leaving again next Thursday.

[@marknewbill-ke7ex]

did the same fix and got a couple more years. however, it came back. the problem is the inner bowl moves down compared to the outer bowl when you sit on it. that movement breaks the seal, even of one applied like in the video. I am not buying a 320 to see if it is better.

[@graysonanddad4938]

Thanks for sharing. I will try this when i return to my camper this week. I'm concerned though because the smell doesn't SEEM to be coming from the toilet, tank, or any drains but amells strongest around one wall. This is my first camper and I don't really know what I'm doing, but i may as well try this. Also, I read that I could possibly have a clogged black tank vent? Ill investigate that as well, but trying in the meantime not to panic that my $40k camper smells like an open sewer... 😅

[@firesideweekenders]

Good luck. It def could be a number of things but this is a good start

[@signature_elle4367]

We were having the same problem with ours. Dometic just sent us the replacement for the recall, but we all already know it’s probably gonna be crap too so I’m sealing it before I install it. Just to be safe. I also checked our vent stack but it looks clear. I remembered this video from when we initially had the problem and told myself once they sent the replacement I would seal it before installing it. One thing that I did when I wasn’t sure if the smell was coming from the back of the toilet was, I put a black tank sanitizing tablet inside the back of toilet. If that helps with the smell or you can smell the thing dissolving it probably means there’s liquid in your toilet. We have a 2020 keystone bullet so relatively new and I was also feeling some type of way like did we just spend $30,000 on a bunch of issues lol? I’ve heard that the replacement is it any better so I’m hoping sealing it does the trick if not, I’m just gonna go ahead and buy the 310.

[@DOUTLAWZ23]

Thank you sir! Had the same problem, followed your instructions and it worked out well.

[@jennifercowgill2838]

thankyou so much for fixing our camper toliet problem, we have had this happen several times . we called dometic and they are sending us a new 300 toliet

[@firesideweekenders]

Glad we could help

[@gregstoots1893]

Enjoy your videos what kind of silicone sealant did you use? I knew it's Dynaflex but what's the full name?

[@firesideweekenders]

Sorry, I don’t have the full name anymore but in the future I would probably use 5200 marine caulk like another viewer suggested. It is more permanent.

[@kylezenklusen2041]

Nice mod vid as usual. Your doin a great job, always super informative. Note that they dont always leak though...regardless, it is preventative and helps. Thanks for the vid, keep. It up!

[@firesideweekenders]

Thank you.Yeah, I know but I rather do it now, than when its a mess lol. If this doesn't work, we will look at other options other than replacing for the same one.

[@kylezenklusen2041]

@@firesideweekenders p.s install a siphon 360 plumbing vent. 1 it will help with the odors as it creates a negative pressure , and 2 it helps disintegrate all the matter so it ends up costing less in blank tank products. Will still have to use em, but you will use less.... have a good one!

[@firesideweekenders]

@@kylezenklusen2041 I saw this recently and wanted to do it until I found out I have to remove the eternabond tape I just put down. I literally saw the video that same day. Soooo I’m going to wait a little on this.

[@g1ow0rm]

Thank you, thank you, thank you. The smell is gone and I can't be happier.

[@firesideweekenders]

You are so welcome! I am glad it fixed your issue

[@toneilmt]

Word of caution to users of a "replacement" 300 - we had the same experience with a newly purchased 2019 travel trailer - dometic 300 toilet worked great the first year, then experienced the internal leaking and odor issue in 2020. After getting a warranty replacement in 2020, it worked for one trip, then same failure. I took it apart and it is the "new" two-gasket model - which failed just the same. I'm now replacing with the 310 model. My recommendation is to either fix it with sealant per this great video, or replace with a 310 (or 320 if room allows)

[@firesideweekenders]

Thanks for watching the video. I have heard similar experience from others in regards to the replacements. Hopefully this holds you over a lot longer than one trip lol.

[@dpd653]

Hey just wanted to say thanks your video was one that helped me do the swap out and reseal the new unit. Appreciate it

[@firesideweekenders]

We are very happy it helped you. Thank you for watching.

[@JeffW-j2r]

Great video - I have the leak; however, I only have the square ring and under it is a plastic spacer ring - is this normal? Do I need to get an o-ring also? If so, where and what size is it? Thanks

[@firesideweekenders]

Are you sure you have the dometic 300? Haven’t seen that before. May need to call dometic. It could just be how they are made now.

[@FridgeRaider83]

Awesome video. I had the same issue with mine just recently. I ended up ordering the 320 model with the porcelain bowl instead of trying the silicon method with the 300. Supposed to arrive Saturday. Will see how it goes.

[@firesideweekenders]

Thank you. Good luck with the new toilet.

[@duaneclare6653]

Having the same problem with my Heartland Sundance (2020). Thinking about doing this mod. Is it still holding up?

[@firesideweekenders]

No issues yet.

[@lizaman7150]

Hi, thank you for sharing this video. I think we're having the same issue on our toilet. Our toilet is starting to smell stinky so we wanted to prevent whatever that is happening. May I ask where did you buy the rubber/sealer?

[@firesideweekenders]

Oh no. Hopefully this can fix it for you. I just bought it at Home Depot. Any local hardware store should have it.

[@kerrykc1]

That was good to know great information I like the way that you talk your way through your project that you are taking care of nice and calm

[@firesideweekenders]

Thank you for the feedback and watching the video.

[@TorontoAreaNestBox]

Thanks for the video; very well explained. Once you do this caulking fix once, will the toilet every come apart again for a second fix if the problem reoccurs? My experience with silicone caulk is it's very adhesive!

[@firesideweekenders]

Yea you will be able to remove it. It’s not glue. It may be just a little extra pressure to pull it apart but nothing crazy. Then all you have to do is remove/clean up the old caulk before applying the new seal.

[@TorontoAreaNestBox]

@@firesideweekenders Thanks very much!

[@robertdahlgren622]

I had the exact same problem on my 2018 Rockwood Mini Lite. Very sad to see that Dometic still hasn’t fixed the problem. I replaced my Dometic 300 toilet with a Dometic 320. Not all RVs will be able to swap the 300 for the 320. Dometic should have made all 300 series toilets have the same offset from the wall so that it would be easy to upgrade.

[@firesideweekenders]

Yeah, we couldn’t fit the 310. It would have been real nice. Not sure why they continue to have issues but it definitely needs to be addressed.

[@edharris5714]

Thank you very much for sharing your experience.

[@vociferonheraldofthewinter2284]

I'd been sold on the Dometic 310, but now I'm having doubts. I don't know if I want to deal with a company that doesn't value their customers and stand behind their products. The company could've put a shine on their reputation and fostered a strong and loyal base for a generation had they acted right. People forgive mistakes when they're handled honorably. But damn, we remember forever when they're not.

[@manuelramon9223]

Thank you for this video, really helped me resolve my issue!!

[@firesideweekenders]

You are welcome. Thanks for watching.

[@Weezieweeks]

Just a follow up - we did not do the seal correctly, but will wait to try again. My husband called Dometic and they are sending us a new toilet!

[@firesideweekenders]

I am glad dometic is sending you a new one. I hope it works and you do not need to do this. Thank you for the follow up.

[@dad2girls603]

I have a tube of DAP ultra clear which I've used on areas of the camper. Could that be used? I've got to fix mine tomorrow. Ugh

[@firesideweekenders]

I don’t see why not. Just make sure to read the label to confirm.

[@Burro2go]

Good work !😊

[@jeanettee1972]

I have a 2022 Salem FSX 178BHSK and I installed the Dometic 310 in my bathroom and it fit perfectly. I love it because it has a wood toilet seat and it has the slow close feature. The flush is really nice too and the porcelain bowl stays so clean. Not sure why it worked so well in mine, I did not have to turn the toilet sideways!

[@firesideweekenders]

Oh that is nice. They def could have plumbed everything different to allow for this upgrade in the 2022 ones. I think also some may have had the holes cut at different measurements.

[@Thecarcissist12]

Currently fixing mine, dometic didn't even put the 2nd gasket on that piece, I only had the one

[@firesideweekenders]

Hopefully you got this fixed

[@williambostwick4769]

I did the exact same repair and did not hold back on silicone. Two 4 day trips and it leaks again. I have my third 300 and will fill the entire void between the bowls with an epoxy or similar substance. My goal is to occupy the space so urine can’t.

[@davidcooper3871]

Same problem with our 310 toilet. Different seal donut between bowl and pedestal. Dometic really screwed up with the hollow base design and tiny gasket. They are screwing up by not offering a proper repair kit with new screws and gaskets, and in the case of the 310, new nylon grommet nuts!

[@danstump3686]

I reused the old gasket on mine by using spray adhesive and hi-temp orange silicone. To attach the bowl there's a dud on ebay that 3d prints the four nuts you need. He doesn't sell the gaskets - just the nuts. Then use it until it works it's self loose again. It's been 8 months and still working.

[@davidcooper3871]

@@danstump3686 Exactly, listed on eBay as Dometic 310/311 Toilet - Pedestal to Bowl Leak Repair Kit

[@renewinnik568]

You had mentioned that there is another manufacture that is pretty much a direct replacement for the 300. Would provide a link to the item. Thanks

[@firesideweekenders]

www.campingworld.com/aqua-magic-style-ii-high-profile-white-17-12-35653.html

[@patrickbrown7398]

Thanks!

[@billturton1839]

Thank you, thank you we just the repair. Hopefully fixes the issue for now. I will call the company for a replacement. Bill

[@firesideweekenders]

That is great to hear. Glad we were able to help.

[@jaysworld126]

Thanks for the very informative video. You may have solved my mystery.

[@firesideweekenders]

You’re welcome. Hope it helped

[@jaysworld126]

@@firesideweekenders There was alot of nasty water in there. Piss poor design. Thanks alot!

[@geraldgauthier8717]

GREAT VIDEO ...Thank you

[@frankperry1543]

Excellent video, Thanks!!

[@firesideweekenders]

Thank you

[@frankperry1543]

@@firesideweekenders I came across your video while searching how to replace the valve in my Dometic 300. After watching you, I figured I might as well disassemble the whole thing and follow your advice. Please keep the good tips coming.

[@firesideweekenders]

@@frankperry1543 thank you for the feedback. We are glad you found the video helpful. Happy camping!

[@christinamycoff7302]

Outside hose put a dip in it .helps with smell and the poop flies that live in the sewer. Every cleaning i dump half gallon of fabo lavender down the toilet.

[@firesideweekenders]

It’s not caused by the outside unfortunately some of these toilets collect pee and feces water in a cavity behind or underneath the bowl.

[@mikeraftis6332]

The 310 has the same problem. Mine leaks and filled with piss. Just rebuilt it.

[@debrawilson3840]

Oh, thank you!!!! We already have this disgusting problem!!! Apparently everyone has this problem with the 300. If we had only known!! Well, now we get to do the fix! Ick!!

[@debrawilson3840]

We decided we're going to replace it, and take the preventative measures before we install it. Thanks again!

[@benitomartinez7876]

That last seal where can I find one

[@firesideweekenders]

I’m sure if you call domestic they can give you a part number and either buy from them, Amazon or camping world.

[@bastropplant5592]

You make it look so easy!!! lol

[@firesideweekenders]

Hahaha. This one wasn’t bad. Luckily it was never used when I did it.

[@owensmith3715]

Great vid job for tomorrow many thanks.

[@firesideweekenders]

Thank you. Don’t get too dirty.

[@sandraberry8049]

The question is since you've done this did it fix the problem permanently. Because I'm wondering if I should invest money into a different model.

[@firesideweekenders]

I haven’t had the issue but at the same time this is caulk. So I would assume at some point, it will need to be done again.

[@kylezenklusen2041]

Hey riccardo been a while. No new vids... we miss ya. Get the slide fixed yet??

[@firesideweekenders]

I know I am sorry. Camping season is making it hard lol. I am working on one now. Hopefully it will be done soon.

[@goodmorningamericashow6535]

So I e ordered now so I fix the new one? Or has it been corrected by the manufacturer? Don’t want to instal then have to take it out again! I’m 75 years old and not that mobile! JDLEE

[@firesideweekenders]

I would do it now before you install it but that’s my opinion. They say they fixed it but some people still have the issue. It’s a hit and miss honestly

[@dbill12478]

I've had raw sewage smell in my rv for over a year. Come to find out it's because dometic knew there was an issue with this toilet but refuse to issue a recall. They told me it's not a safety issue lol. Offered to send me the modified same toilet that has already been replaced once. Would not upgrade me to another if I even paid the difference. Completely ridiculous this toilet is being sold and was put into so many campers. they will not take responsibility for a major heath issue they are responsible for. Unfortunately they make about everything in these campers so you can't stay away from them. I will spend my money on anything other than dometic products. In the future.

[@goodmorningamericashow6535]

@@dbill12478 I’m not sure as to the reason you are having problems, but my sewer is straight through and doesn’t collect in a black tank! The shower does collect in a gray tank and mixes with the sewer line with a no back up valve. This is why I believe mine seems to be working fine!

[@shannonshirk1079]

@@firesideweekenders same problem with a 2 month old 320. over hour on the support line and they are sending a new one, but assume will have the same problems. Will do the silicone before installation.

[@thericardocartagena]

@@shannonshirk1079 let me know if the issue does come back. I hope it doesn’t. Glad they replaced it thought.

[@PilotCooking]

The smaller O ring is NOT the source on the LEAK .... Its the larger flange gasget between the base and bowl.

[@onehotpotatoe]

Not always true. Just pulled mine a part and it’s leaking at the center too. The base was not leaking at all.

[@obus4186]

May I suggest nitrile gloves

[@firesideweekenders]

The bathroom had never been used. It was a brand new trailer. I felt it was safe enough.

[@tko6196]

Don't waste your time just caulk around the water at the back side and if you remove wash and add caulk on the back of the water line. Before it becomes a problem.