08-03-2014, 11:31 AM
I've had that problem as well even though I had "disabled" the vacuum breaker. ( Maybe because I allow non-Newell owners to use my facilities ! B-) I found that the trap in the shower dries out enough to let gas escape. I need to remember to run a bit of water into each drain if they have not been used for a while.
1993 Newell (316) 45' 8V92,towing an Imperial open trailer or RnR custom built enclosed trailer. FMCA#232958 '67 Airstream Overlander 27' '67GTO,'76TransAm,'52Chevy panel, 2000 Corvette "Lingenfelter"modified, '23 Grand Cherokee.