I need help to eliminate a sewer smell coming from the sliding door area going upstairs in our fifth wheel. The door is on the opposite side of the toilet. There are no leaks. I have looks underneath ...
Get a clear fitting. Dump, fill with some water, dump, fill, repeat until it runs clean. You will likely be amazed at how much "stuff" is left in the tank with just a simple dump. I have to fill/dump several times to get it all out. And before all the backseat campers ask, yes, I am using plenty of water to start with after a dump and during usage.