Brand new 2024 Keystone RV Cougar 29BHL.
Hooked up to the black tank flush and it does not function. I have a hose with atleast 60 psi behind it and nothing. Is there a valve that isn’t turned? Doesn’t work with tank valve pulled to open position either.
Check valve could be installed backwards. Mine was when I got the RV. Mine’s a Keystone too.
Line can be linked or crushed,l or the check valve on backwards.
Check valve will be either in your vanity in the bathroom or right beside the tank itself.
To check for kinks or crushes, you’ll have to open the underbelly up and trace the lines visually.
Of course, if it’s under warranty, let a dealer deal with it.
2 keystones owned. Both had issues with the black tank flush. Both were at the anti siphon valve. Both leaked and put water inside on the floor. 1st location was under the bathroom sink. The valve itself was bad. The second was in my 5th wheel, it was located behind the shower stall. I was able to remove the shower controls and access it through that opening. It just needed tightened.
Source: Black tank flush not working
