PackerFan beat me to it! It sounds like he may have hit the nail on the head to me. We have a 3582RL also and have not had a problem(knock on wood
) with our toilet so far and if we do it will be replaced with a Dometic unit but until then it's the Thetford but before heading out this year, I'm putting shutoff valves on all of the water lines period just to be on the safe side. Check past posts about problems with the toilets but most of them you would be hearing or seeing the water running. Let us know what you come up with.