What To Do If Thetford Toilet Does Not Hold Water And Always Has Bad Odor?
Updated 09/25/2025 | Published 09/15/2025
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Question:
i have a 2003 cascade. toilet thetford 20920. Not holding water in holding tank so always has bad odor?
asked by: Betty S
Expert Reply:
Hello Betty, thanks for reaching out. It sounds like your flush ball seal is bad. They can warp or crack which causes water to leak and lets bad smells out. We may have the seal you need, but I was not able to find any good references to the part number you provided. Even the Thetford site didn't show anything. The flush ball seals are largely model specific.
For example, the Replacement Waste Ball Seal # TH34FR33AB is for the Thetford AquaMagic Style II toilet like part # TH35SE. So if this is what you have, replacing the flush ball seal should resolve the issue.
Product Page this Question was Asked From
Replacement Waste Ball Seal for Thetford AquaMagic Style II Toilet
- Accessories and Parts
- RV Toilets
- Seals and Gaskets
- Flush Ball Seal
- Thetford
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Betty S.
9/25/2025
Not sure if I asked the question correctly. I don't think it's the actual above the floor toilet portion that is leaking. When I do a pump out, I add 5 bowl full of water to the holding take to avoid odor (parts per million). That water does not stay there and seeps out therefore each time the toilet is used it is waste only with no water and thus bad odor. The last time I did a pump out, the end of a plastic coat hanger came out and that's when the problem started. What is the bladder seal? Do you think that is something that would solve my problem.