My Dometic Toilet Will Not Hold Water Is The Bowl What Do I Do?

Updated 08/03/2026 | Published 07/13/2023

Question:

I bought a dometic ceramic rv toilet a couple of months back and the water in the bowl will not stay. I have taken out seal looks fine, put a little vaseline on gasket but still leaks all the water out of the bowl within a couple of minutes. Need help. Thanks

asked by: Fred M

Expert Reply:

This is a known issue with some of these Dometic toilets here within the last year or so. The bowl seal may have a very slight deformity and it allows water to leak out. This will be covered under warranty thru Dometic. If the unit has not been used you can send it back and get a new unit. If it has been used/installed, obviously we could not accept a return, and Dometic would have you take it to one of their technicians for inspection/repair.

expert reply by: Jesse M

Don U.

7/11/2024

Jesse, I am experiencing the same issue, and I’ve replaced the flush ball seal 3 times over the last year. If it’s a defect in the seal, is that the seal you mention? If so, is that defect so consistent that the 4 seals I’ve received from Dometic have all had it? After the first replacement (2nd seal), I figured it was a defect, so I didn’t do anything different. After the second replacement, I used seal conditioner, and it lasted about a month, then started using plumbers silicon grease, which lasted about another month. Then I read we shouldn’t be using harsh cleaners (we’d been using bleach wipes and regular toilet scrub cleaner), so we ordered a 3rd seal. We’ve only been using dish soap on the bowl, and still using silicon grease. This 4th seal has just started to not hold water anymore. I’m at my wits end with this thing. Is the defect with the seal, or the toilet itself? Thanks for any information you may be able to provide. Bought Oct ‘22 - bought RV new June ‘23 - 1st replacement March ‘24 - 2nd replacement June ‘24 - 3rd replacement Current- this 4th seal just started failing/letting water drain from bowl this week.

Jesse M.

7/16/2024

@DonU Hey Don, thanks for reaching out. I am sorry to hear you are having this reoccurring issue with the bowl seal. Unfortunately, this issue is not uncommon with the Dometic RV toilets. Based on what we hear from Dometic, and the feedback we get from other customers, the issue is mainly with the seal itself, and the way it fits in the bowl. So, you could argue that the shape of the bowl is not ideal for the seal. From what I hear the seal material is just not good quality. Another new seal may fix the issue temporarily, but the same thing will probably keep happening. If it were me, I would consider going with a different brand of toilet like a Thetford. The link below will show you our full selection of Thetford RV toilets.

Helpful Links

dept-pg-rv_toilets-pm-thetford.aspx

Don U.

7/16/2024

Thanks, @JesseM! Replacing the toilet was my next move, but wanted to make sure I’ve exhausted all other options first.

Artie C.

10/26/2024

2 seal later I said f*** it and took a hand torch to the seal, molded it to the toilet and hasn’t leaked yet lmfao

John

2/3/2026

@ArtieCwhat toilet do you recommend to replace the high profile domestic 310.

Jesse M.

2/4/2026

@John hey John, the best option we have for that is the standard height 310 part # DOM37FR (tan) or # DOM57FR (white)

Rebecca

8/2/2026

NEVER USE VASELINE! Vaseline is a petroleum product. The gasket is a petroleum product. Petroleum eats petroleum!!! If you want the seal to NEVER seal ever and constantly let the funk in, then use Vaseline. If not, USE SILICONE PLUMBERS GREASE!!