Yahoo Message Number: 11013 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/11013)
Just catching up on some of the posts and read the discussion on holding tanks. We just completed a three month trip to the SW and I discovered one of the causes of tank oder inside the coach.
I am not disputing any of the previous recommendations of different venting techniques. This may work as well, but I discovered that all my odors were originated from the grey water tank and the odors were coming up through the "P"-traps. I found that by dumping my grey water tank when it was 1/2 or more full and opening the dump valve completely was causing a suction in the grey water drain system. The suction was sufficient to suck out the residual water in the "p"-traps. The main culprits were the traps for the shower and washer.
Solution: Opening the dump valve so it drains slower or make sure that after draining the grey tank, run water through all the traps so they are full. This also should include the washer drain. A quick cycle of water fill and the spin/drain cycle will do the trick.
After this discovery, no more orders going down the road.
Jim Hughes
2000 Allure #30511