Toilet bowl doesn't hold water

I think I will use dawn to clean and get the thetford conditioner....looks like a bottle is $6 that will do a number of treatments

Thanks folks

Before you start running for parts:

Just a tiny piece of toilet paper will prevent it from sealing.

Get a brush with a long handle and hold open blade and run the brush around the opening to clean.

Every time mine wouldn't seal the brush cleaning fixed the problem.

Thetford makes a toilet bowl seal conditioner. Softens the seal, we had the same problem, bought the conditioner, cleaned the "Rim" with a small brush, added the conditioner. No more leaking ! Just took one treatment, now when storing the 5'er between trips pour a bit in the bowl, and flush it before we leave on the trip. Good Luck and Happy Camping !!!

NMDriver, if it was me I wouldn't put cooking oil in there while in storage. I would think the oil would get rancid and very smelly if it set very long. We put RV antifreeze in our toilet when storing it. The antifreeze doesn't evaporate like water and won't get smelly over time. JMHO

Cooking oil sounds like a good idea. We have canola oil saved from frying tortillas. My seal works fine to hold water, but the water evaporates pretty fast in the summer. I will try the oil just to keep the evaporation lower during storage.

NEVER use a petroleum based product like Vaseline on your gasket!! Best thing to do after cleaning is to use plumbers silicon or fill the toilet with olive oil. Any time our toilet is going to sit unused we drain the water and put olive oil in. Never a problem.

If it is the Dometic 300 series, it is likely the ball valve has slipped out of one of its pivot mounts. Get a flashlight, turn off the water, open the valve and look. If it's off, you'll have to reach down there and put it back into place.

We just got a new to us Fifth Wheel and the toilet would not hold water. After fooling with one in another rv we had I just replaced the whole toilet. Cleaning and lubing works a lot of the time but there was just something about messing with something we did't put there.

Use rubber gloves, and soak a cloth in a little dish soap. Open the bowl and clean both sides of the gasket,rinse with water and use dry cloth to wipe again,then add a little vasalean to the rubber gasket,wipe inside and outside of gasket and give it a try. If still leaks a new gasket may be needed.