Commode not holding water

My SeaLand only holds water about half the time. Make no difference to me - it doesn't smell or anything when it leaks out.

I won't be replacing this ceramic toilet that looks better than the ones in our house.....I think it might be a Thetford but not sure....I just looked through all the paper work and the pull out dump deal is that brand but it don't say what the throne is.

Mine is a Sealand and it is really quite easy. Two piece toilet and the top is held to the bottom by what looks like an oversize hose clamp. Loosen the clamp and the top lifts off and exposes the ball and seal.
At about 3 yrs mine stopped holding water. Took it apart, cleaned the rubber seal and lubed it with Pam (per Sealand rep) and it then held fine. ....
Until this year 4 yrs later. This time cleaning did not help as rubber had hardened. Replaced the rubber seal and all is well again.
Less than an hour even when not in a hurry.

CLR is a good cleaner for the buildup.

Before you do anything else, try the vinegar. It that sort of helps then use some muriatic acid or LCR like stuff. That may work because the typical fouling is calcium papitate.

Then again, you may have to get in there and really clean it or replace the seal, but they the easy stuff first.

Matt - once a Thetford engineer

This is what mine looks like closed. When you push down on the pedal, it moves back towards you to open and flush.

Provide the make/model and we'll find a kit for you. Seem to be getting a lot of these posts lately.

It may be easier to replace the entire commode. If it's a few years old it may be time anyway.

Guess I need to go see what kind it is----looks like a "ball" that rotates when I push the pedal down and a rubber seal? around the outside ring. That make any sense????

I just did this about 10 minutes ago. My valve wouldn't close all the way everytime and just last week, it got stuck open. I applied plumbers grease around the opening being sure to get it into the grove wearing a glove of course. I hope it works. It was cheap anyway. $1.97

I had this problem (after letting my seal get dry, from not having some water sit on it).
Thetford makes a product to "renew" the seal - worked great on my "blade" style toilet.