Originally Posted by Igo96047
I have a 2013 25B25FB and my gray water tank won't drain properly. I put a bunch of tank cleaner in and it helped but didn't solve the problem completely. Anybody know anything about the inside of the gray water tank?
Sounds like the vent tube has a blockage or maybe the drain tube is kinked. Both situations can cause it to drain very slowly.
Air has to be able to enter to displace the volume of water that is exiting. So a compromised vent tube can significantly slow down the speed at which water exits the tank.
I don't know how the tank on your trailer is vented. But on my Sunrader I had a blockage in my tank because the vent pipe that went up to the roof fitting had slid downwards and was then beneath the level of the surface of the liquid. Which of course meant that there was no longer an effective vent as no air could enter the tank. Things like that can make it difficult to figure out the cause of the issue.