Toilet bowl seal

[Silversands]

As an unfortunate result of filling the black tank with rinsewater and not monitoring it closely our black tank overflowed into our toilet. Now the seal in the toilet appears to be broken- the toilet just st drains as it is used and will not hold any water even though it appears closed. Now we are getting a musty smell because there is no small amount of freshwater sitting in the bowl in between uses.
Any advice on how to repair the seal that apparently was damaged when water came up the toilet bowl through the black tank?

[SSquared]

We have a 2013 25FB. The toilet is a Dometic 310. You may have the same model.

The seal on ours worked fine at first but did start leaking after a couple years. The black seal piece is replaceable. My wife bought one online (probably at Dyer's but I'm not sure) and put it in without too much trouble, but I can't give you specific instructions.

[A W Warn]

Originally Posted by Silversands

As an unfortunate result of filling the black tank with rinsewater and not monitoring it closely our black tank overflowed into our toilet. Now the seal in the toilet appears to be broken- the toilet just st drains as it is used and will not hold any water even though it appears closed. Now we are getting a musty smell because there is no small amount of freshwater sitting in the bowl in between uses.
Any advice on how to repair the seal that apparently was damaged when water came up the toilet bowl through the black tank?

I'm assuming you are talking about the flapper seal that is inside the bowl, not the foam doughnut seal that is at the base of the toilet between the toilet flange and toilet:
I doubt that the flapper seal is broken. When the tank was overfilled there might have been some floating debris. There is a groove that the flapper slides in that can become impacted with paper/poo, etc. It can be cleaned with a stiff brush or a special tool that Thetford sells for this purpose. I made a similar tool by bending a small diameter flat blade long handled screwdriver.
http://www.thetford.com/wp-content/u...crewdriver.pdf