Holding tank odor

[Richard Peterson]

For what it is worth, this might save someone some time.  I have noticed a smell from the black water holding tank off and on since I've owned my 77 rear kitchen.  When I was restoring this unit, I had removed both holding tanks, and re-sealed them so was pretty sure the odor was not coming from those openings.  I thought it was a trap gone dry or something like that.  Well, after an extended stay in Mexico, I noticed the odor while using the stool and decided to see if the vent pipe was not really sealed.  I removed the top of the housing which surrounds the vent pipe along the wall and saw that the vent had a gap of about 2" between the end of the pipe going to the roof and the fitting going to the tank.  A trip to the hardware store for some extra fittings and pipe cement solved the problem.  Hope this helps you if you can't find an odor source!