Replacement Bottom Gasket and Hardware for Lippert Flow Max and Dometic 310 and 320 RV Toilets

Updated 04/06/2026 | Published 03/31/2026

Question:

When you install the Dometic 310 floor flange seal/ gasket should you use sealant to the base of the toilet? thank you

asked by: Sandy S

Expert Reply:

No, you should not Sandy. The Replacement Bottom Gasket item # LC88AF does not need any additional sealant or caulk when you reinstall your toilet.

The Replacement Bottom Gasket item # LC88AF provides the necessary seal between the toilet and the waste pipe. Adding sealant at the base will trap any leaks down the road, which would cause the water to run elsewhere like beneath your subfloor.

What model toilet do you have?

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expert reply by: Jerred H

LC88AF
(click to enlarge)

Sandy S.

4/6/2026

Jerred H I have the Dometic 310 two years old, the flush ball sealhas leaked from day 1, tried silicone, new seals, adjust the ball, make sure the ball on one side is in track, warm water on the seal, etc, etc, so I took the toilet loose and wanted to check inside, all seems ok, and wanted info as to installing the toilet to flloor flange seal, thank you It appears Dometic does not have a Flush ball replacement with spring and screws as it does for other models, will be keeping this one a short while and then replacement with non Dometic that shows parts can be easily replaced, Thank you Sandy

Jerred H.

4/6/2026

@SandyS You're welcome! Yeah, given your issues with ongoing leaks you definitely don't want to push that water somewhere else. The lack of a replacement flush ball valve for the Dometic 310's is a constant frustration to us as well. If you have any additional questions, don't hesitate to reach out.