[MaxwellD]

Originally Posted by Rondo

Max- I would do as Ram Montana High Country stated and replace that HEPA valve. It can be accessed, I think, by taking out the basement storage wall and getting under the shower area and taking the damaged one out and replacing it with another or a "p" trap. The gray tank will not give off the bad odors that the black tank but it will still give you sewer gasses when you dump the gray. Better safe than sorry, the way I look at it!

Glad you found the problem and now you know how to fix it if it should happen again on another drain.

Me too - I should have been suspicious seeing that the black colored valve handle was labeled as Grey - but I'm a little slow. My Monty is a FL - so the shower is in the back. I am afraid that access is going to through the belly - if in fact there was a HepaVo trap there - I still am not sure.
Thanks for your help