Grey tank surge...

[Longshore]

My WC 890 has a 30 gal grey tank. The shower is north of the dinette, right behind the wall on the right side. Coming down a grade with the grey tank 1/2 full I got a pretty good surge of it into the shower pan. It was all contained, but I did have to empty the house of air fresheners when I got home. Obviously the solution is to put a test plug into the drain when traveling to keep the stink water in the tank. The drain measures 1&3/4 " id so a 1&1/2" test plug will do the trick.

Anybody who buys one of these campers will have to confront this issue.

[amosnandy]

I thought there was supposed to be a back flow valve in the p trap under a shower. Is it under warranty. Take it to the dealer.

[Old-Biscuit]

Shower drain to/thru 'P' trap to grey tank...no backflow preventer

That is why shower backs up when a grey tank is Full

Pop up silicone stopper
https://topdealslab.com/shower-drain...hower-bathtub/

Place in drain then push down...it closes/seals off drain hole
*replaces the shower drain cover