jplante4 wrote:
HappyKayakers wrote:
Has he tried taking apart the dump valve to look for a cutout blocking the exit hole?
If it's a BRAND NEW coach, this is most likely the issue. The cutout from the hole the factory punched to put the drain piping into the tank is roaming around the tank. Even if you back flush and get it working for a while, eventually the cutout will make it's way back to cover the drain.
Ah yes the infamous Georgetown plastic disk in the tank problem! We've been battling this since 2011 on our unit. The Georgetown factory warranty folks have admitted that it is a problem but I've found the solution without having to drive to Indiana to have it fixed. When the gray is blocked to a trickle this is what I do. It sounds complicated but really isn't:
Notice that the black tank and gray tank both drain into the same outlet that you connect hose to.
Buy and install a third gate valve on the outlet that the hose is connected to. You can get this twist on third valve from any RV store.
Close the third valve.
Open the BLACK valve and any liquid in the black tank will force the air bubble trapped between the three valves and blow the disk that was left over from construction that's plugging the gray tank drain hole away from the opening. Only open the black valve long enough to hear the gurgling stop. Maybe a second...then close the black valve.
Now open the third valve that you purchased and the gray will drain!
If you have a problem with black possibly going into the gray tank then first drain the black tank and refill to maybe a third with the tank flush system and then do the procedure.
Have fun!