Monday, September 25, 2023


A simple fix for a toilet bowl that’s not holding water

Our toilet bowl is not holding water and we need a simple fix. Everywhere we researched said we needed a new toilet bowl seal. Unfortunately, that meant completely removing the toilet to replace it. Even worse, every RV tech we talked to said “Nope,” they “don’t do toilets.”

No toilets in stock

Even Tiffin won’t replace seals, they replace the whole toilet. The smell was so bad in our RV’s toilet that we considered replacing the whole thing like they were suggesting, but just like so many other supply chain problems, there weren’t any toilets in stock to do so.

YouTube, a DIYer’s friend

After spending a morning watching YouTube videos about toilet bowls not holding water and looking for a simple fix, I heard someone say something interesting in the background. In this video, a man was showing the viewer how to remove the toilet. His wife, who was filming, said in the background, “Plumber’s grease can buy you a couple of months.”

Plumber’s grease to the rescue

Thank you, background wife! I raced to the hardware store and bought plumber’s grease. I turned off the water, put on a glove, and thoroughly spread plumbers grease on the top and bottom of the toilet bowl seal.

Plumber’s grease. Photo credit: Nanci Dixon

Found our simple fix for the toilet bowl not holding water

It worked! I discovered that the odor that sometimes permeated the motorhome when driving was not the vent, it was the toilet seal. We will take this short-term fix and order the seal. I’ll review this diagram to learn more.

Or perhaps we can find a tech that will actually touch a toilet…


Speaking of toilet troubles… This woman fell headfirst into a pit toilet trying to fetch her cell phone. Yikes.


Nanci Dixon
Nanci Dixon
Nanci Dixon has been a full-time RVer living “The Dream” for the last six years and an avid RVer for decades more! She works and travels across the country in a 40’ motorhome with her husband. Having been a professional food photographer for many years, she enjoys snapping photos of food, landscapes and an occasional person. They winter in Arizona and love boondocking in the desert. They also enjoy work camping in a regional park. Most of all, she loves to travel.


  1. There is something more simpler then Plumbers Grease that we use.
    Vasaline works jst as good and cheeper. Aply the same way as Plumbers Grease.

    Very simple fix…

  2. Mine was easy to fix and I didn’t have to use any grease or lube or anything. I got a new seal and was going to replace it, but as much as I pushed down on the old seal to remove it, it would not come out. I was afraid to use too much pressure on it for fear it would break and parts would fall into the tank. I quit doing that but wondered.. “did pushing it down a little bit help?” Lo and behold, it did! It holds water no problem now. Just a little bit of downward adjustment and we’re good.

  3. My husband just replaced the seal in the toilet bowl a couple of weeks ago. Took LESS than an hour! I think he ordered it from Amazon. Anyway, bowl holds water now just like new!

  4. What a confusing article and comments!

    The seal that holds water in the bowl is easy to replace without removing the toilet.

    Odor can come through either this seal or the floor seal

    The floor seal needs the toilet removed to replace which is somewhat harder.

  5. We used silicone grease applying it to the seal profusely. It has lasted 4 years. Also used it on the flapper valve on home toilet 5 years ago.

  6. I have replaced the bowl seal on our Sealand china toilet several times over the years. Had a mobile guy do it once after I had knee surgery. Mobile guy replaced the 20 yr old toilet last week after new seal didn’t fix the leak … I ordered the toilet from Amazon standard shipping & it arrived two days later!

  7. toilet seals 2 one for floor & one for ball valve is part of my traveling parts selection. (need water valve to complete)
    as others stated YouTube has videos. Just make sure you’re looking at the correct one for your model. (also for getting the correct replacement part!)
    thetford makes a seal conditioner that works well for storage.
    It’s not a hard to do repair

    • You are absolutely correct. I planned on replacing the seal and was looking through the Telford manual before beginning. The first thing I noticed was a warning not to use Pinesol or other cleaners of that type! (Been using Pinesol for 60 years). The next thing suggested was the Telford brand seal conditioner that you mention.
      It really works!!!!!!
      As the old comic line goes “ Try it- you’ll like it”!

    • Our rig is a 1998 Itasca Suncruiser and we tried the Thetford toilet seal and after a few doses the leak was stopped, When we get home we always add some so it sits there until our next trip. Very happy with the results

  8. I have used 303 aerospace protectant with success. Just turn off water, clean seal area, and soak with 303. Sometimes it has required more than one application.

  9. My toilet has a flap that drops down when flushing. While washing out the tank one day with a sprayer, my foot slipped off the pedal and the flapper slammed against the hose, which must have bent the arm a bit as it leaked after that. I simply took a stick with a hook on the end, pushed the foot pedal, reached in with the hook and pulled the flapper back up slightly. Hasn’t leaked since.

  10. If it’s the step on pedal type, press pedal all the way down, while holding it down slide foot off. It will snap up, worked for me in my former RV.

  11. I would think at today’s labor rate it would be cheaper to replace toilet. I went from plastic toilet to porcelain for around $175. (Some years ago). Other than that, loosen bolt and water supply and yank the toilet out, put a rag in hole to keep smell out and repair it. Again labor cost!

  12. you turned a simple fix into a confusing mash of mis-information. The ball valve seal replacement is simple 5 minute job. Lots of youtube information on how to replace the seal

  13. I think you are referring to the blade seal? (the ball valve seal), not the actual base toilet seal from the toilet to the floor. Those are available on Amazon and I’ve replaced a few of them. Yes, there is food grade lube that is used on the seal. Always keep it wet and plenty of water over the valve at all times. If it dries out or gets dirty, it can and will leak. Cleaning is crucial, as Seann mentioned. I usually lube the seal after each dump (gloves of course!)
    Some say it can be replaced while mounted, I prefer to do it while toilet removed. Get the kit to replace all seals! Only 2 bolts hold it down, easy to take apart, even on my Tiffin.

  14. We ran into the same problem a while back. Our local mobile RV repair guy showed us how to remove the seal and give it a good scrubbing (with an old toothbrush). We did not have to remove the toilet to do this. Finally, we got a new seal and installed it when we again ran into a problem. Wifey always tells me she used MY toothbrush . . .

  15. I’ve used a thin layer of petroleum Jelly – Vaseline – for years to keep the toilet seal from drying out.

  16. I bought one of those foam dishwashing brushes and use it to clean the toilet and the toilet seal it has worked well fixed the leaking seal problem and keeps the toilet clean. SPECIAL NOTE DO NOT USE IT FOR CLEANING DISHES AFTER THIS.


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