Hello, we have a 2017 RP 178, used but new to us, and this is our second season. Bought it from friends that I know are pretty careful and we are also about what goes down the drains. The grey tank will not drain and water is backed up in the shower pan. If we run water in the kitchen sink, it backs up more in the shower pan. This is what we have tried:
Ran HOT water in the sink and shower.
Plunged kitchen sink and shower.
Manually snaked the shower, kitchen sink, roof vent, and up the main dump valve. Snake comes out clean and seems to get to the grey tank each time.
One at a time we put compressed air in both sinks, the shower, the roof vent. We blocked all other outlets while putting in the air trying to build a little bit of pressure.
We have not tried soap or the vinegar/baking soda in the drains yet. There doesn't seem to be any residue or a clog we can find with the snake. We thought it was maybe an air lock. We just filled the black tank 2/3 and are going to take a rowdy ride around the neighborhood and go dump the black, flush the black, and try to dump the grey. Will go for the soap, or baking soda vinegar next if that doesn't do it. What the heck else? Thanks in advance for your help!
Camerons