Dometic model 300 odor problem and replacement

A lot of our members were alive well before computers. When you’re over 70 and something happens to replace the computer I hope someone is kind enough to help you out.
 
Dometic 310 replaces 300 garbage

Have had no issues with toilet til this year, 1st time out.

I called today the 1-800 # for Dometic and they wouldn't help me out because I was beyond the 3yr time frame for replacement. No matter the issue of the constant issue with this toilet would they offer a replacement, just to say they are still working on the issue with this toilet.

My trailer is a 2018 Puma 255RKS 5th wheel

So as of last week, I now have the Dometic 310. My dealer came through since I bought the unit from them brand new. Going forward I will never own another plastic toilet again.

Just an FYI I did attempt a repair on the toilet as was in a previous video someone posted but after re-installing it, it would not hold water. I must of put too much silicone into the repair.

Cheers
Dan
 
We had the same problem with our Dometic 300 toilet. I checked the vent (it was fine), pulled the toilet off of the floor and replaced the seal in the base and the seal on the ball valve. Nothing fixed the problem. Then, I read about the internal leak on the Dometic 300 toilet. I contacted Dometic and they said that our 2018 toilet was too old to qualify for replacement. I ordered a new Dometic 310 porcelain toilet, installed it, and end of problem. Many thanks to the earlier post warning about not tipping the old toilet to avoid a nasty accident. Before we started using the new toilet, I treated all of the inner bowl surfaces with the ceramic finish sealer that I used on my truck and now nothing sticks to the bowl.
 
I'm glad that you guys are getting replacements. It's frustrating to buy a new trailer and have a defective toilet. But it is refreshing that Dometic has taken responsibility. We haven't had any issues with the upgraded model 310.

Dometic will only replace toilets in newer RVs. They refused any adjustment on our 4-year old trailer.
 
I changed mine out in about 15 minutes. The water supply line will have a compression connector that will unscrew from the flush valve. Then, pop the covers off of the two mounting bolts and remove the two mounting nuts. The toilet should now be completely loose. Warning!! If your old toilet is a Dometic 300, be sure to keep it completely upright and don't, under any circumstances, tip the toilet or you'll get a nasty surprise! I dropped the old toilet in the new toilet box and set it out for the trash.
 
You would think Dometic would stop producing the Model 300. I replaced mine almost 7 years ago with the same issue and they are still selling them today. Unbelievable!
 
You might want to watch the following video by John Marucci. A good friend of mine had the same problem with his Dometic 300 and Marucci's modification did the trick. He's gone through two seasons with the modified 300 without the smell returning.
 
We had the same issue with the toilet in our 2016 travel trailer. Once I discovered the issue was the Dometic 300 toilet itself, I disconnected the water line, removed the two bolts holding it to the floor, and put the plastic piece of junk in the trash.

I replaced it with a new Dometic 310 as it has the same form, fit, and function. We've never been happier. Didn't bother to inquire of Dometic regarding a replacement.

Bob
 
Too bad the 310 won't fit in my unit. Rear is too close to cabinets, reports are that soft close lid and seat won't stay open due to clearance issues. But lucking out after 5 years with 300, guessing if I don't have problems yet, I'm in the clear.
 
Too bad the 310 won't fit in my unit. Rear is too close to cabinets, reports are that soft close lid and seat won't stay open due to clearance issues. But lucking out after 5 years with 300, guessing if I don't have problems yet, I'm in the clear.

You might be able to scoot the floor flange out/forward enough to get the 310 to fit. I was told by the folks at Dometic that the 300 and the 310 are the same size and fit.

Here is what I found regarding dimensions.

https://www.amazon.com/Dometic-Standard-Toilet-302310031-Height/dp/B073WYHBHX?th=1

Bob
 
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It's CLOSE, but apparently the rear end of the unit where seat attaches protrudes rearwards a little bit further. Somebody on another thread about this said to just cut a notch in the cabinet door behind it to accommodate it, but that would look like hell. If you moved it forward a tad, then the mounting bolts wouldn't line up and the drain hole would be out of alignment, no?


edit: Found the old thread where you get in a little bit of a 'jam' trying to replace the 300 with a 310 complete with pics:
https://www.forestriverforums.com/forums/f34/dometic-320-installed-in-geo-pro-19fbs-183781.html


Thread says 320 but it's actually the 310.
 
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The replacement toilet is exactly the same and had the same issue a month later. I ended up removing it, and buying a different brand. I gave up on dometic toilets.

Mind if I ask what brand and was it a direct replacement or did you have to modify the new one to fit?

Thanks,
Bill
 
Toilet is bad

I just had my dometic 300 replaced! I had followed the lead on line about fixing the seal in the center of it. Took it apart and re -cleaned the hell out of it cuz it had piss inside the other tankers. Two tanks there's the outside tank and the inside tank. It's plastic. There is a YouTube video. How to fix it online! But call dometic. They will send you a new one. I upgraded to the 320 but it came broken. Dometic has been very good to work with and they have a warranty on them.
 
Kohler Santa Rosa compact

Since I was waiting for my new dometic 320I just went ahead and put a house toilet in works great. Had to cut the water line off and put a barb on it and screw it in to shut off valve and works great.
 
Since I was waiting for my new dometic 320I just went ahead and put a house toilet in works great. Had to cut the water line off and put a barb on it and screw it in to shut off valve and works great.
Yikes, that has to weigh a lot. Unless you have a huge RV and weight is of no consequence. And wouldn't flushing a household toilet use a LOT more water?
 
We picked up a new to us 2020 Coachman Cross Trek 20XG and after our first outing we had the oft mentioned, dreaded pee stink. This is our 6th RV and am well versed in the problems and vagaries of RV ownership. But this one had me stumped until I read posts in these forums. So I am grateful for all the people that have chimed in over the last decade on this subject as it literally saved me from going out of my mind.

We had the the Dometic 301 (low profile) and after reading the posts I knew it had to go. I replaced it with the 311 and I must say it is VAST improvement. It was a direct fit so that was good. Working in a tight space (this is a small class C) had its challenges but at least all the tools I've collected over the years got a good workout. Thanks again for all your posts, they're much appreciated.

https://imgur.com/a/Xjz8OKr
 
Toilet replacement

Can anyone please tell me if I can put a dometic 310 toilet in my 2018 Flagstaff 27RLWS? My best guess is it might fit, but not sure.
 

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