Replacement Flush Ball Seal for a Dometic Series 310 Toilet

Updated 10/13/2026 | Published 10/10/2026

Products Featured in This Question

Replacement Flush Ball Seal for Dometic RV Toilet

(112)

$41.87

Question:

Need a Dometic flush ball seal for a Series 310 toilet. The seal diameter is 4 1/4 and ~5/16 thick and interior diameter is 2 7/8. Thank you!

asked by: JANET L

Expert Reply:

Thanks for the information Janet. The Replacement Flush Ball Seal item # DOM63FR is the correct one for your Dometic Series 310 toilet. It is sold individually and has a 4" outer diameter, a 2-3/4" inner diameter, and is 1/5" thick. I don't have a seal that matches your dimensions or know of another one available for the Dometic Series 310 toilets.

What kind of RV do you have? Feel free to answer this and throw in any other questions you have, where it says Add Comment.

expert reply by: Jerred H

DOM63FR
(click to enlarge)

Kevin

10/12/2026

This fixed my issue of the bowl not holding water. I will do a better job keeping this one lubricated.

Jerred H.

10/13/2026

@Kevin Glad the new item # DOM63FR seal was able to get your toilet back to holding water. Thanks for sharing that feedback.

Kathy

10/12/2026

I had purchased cheaper seals from a local rv dealership and also from Amazon. They were no good. I hated paying such a high price but they’re good quality and thicker than the knock offs. So the price is justified in my opinion. I have the Dometic x2 and they fit perfectly. Highly recommended.

Jerred H.

10/13/2026

@Kathy Thanks for that recommendation Kathy! Glad the higher price of the Dometic item # DOM63FR seal was worth the additional cost. I appreciate you coming back and sharing that with us.

Steven B.

10/12/2026

Howdy Janet! Replacing the seal is pretty straightforward. Pulling the old seal out is easy. Installing the new one can test your patience. But once installed, consider putting a little bit of Vaseline to the underside of the seal. It helps. Enjoy!