oder problem

Currently have the same problem. Someone suggested the air admittance valve and if that is the case we would be smelling the gray tank and not the black so I suppose this is a possibility. I have heard the gray can smell just as bad as the black. MH has been winterized now so won't be able to investigate further till spring. We also had an issue when new where the rubber coupler between the gate valve and the macerator came loose. When to dump and got a nasty surprise. Still trying to get the smell out from that incident. Noticed the other day that it is trying to slip off again so I see another repair on this in the future. Another suspect was having one of the vents open while traveling and it sucking in fumes but upon further testing I don't think that is the problem.

gbopp wrote:
Check for an air admittance valve under the sink. Maybe have it's bad.

X2....bet this is the problem. Very common problem.

Ron

Where is your water heater located? I started smelling the rotten egg smell after the coach had sat for a while. I usually drain out the water heater when it's going to be a few weeks between trips, but didn't that last time prior to smelling it. Drained it, flushed it and there was no more smell. Just a thought.

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IF you thinkit is the stack, If you can take a hose and run water from the top of the coach down into the tank. That should clear the stack and not cost anything

I had a similar situation. I used some bleach and calgon water softener. Filled it up to 3/4 full. When I arrived to the campground I dumped the tank leaving the fresh water flush going for an hr. Just remember to leave the dump valve open. Besides solving the odor problem my sensors started working again. Keep those tanks clean. Good luck.

A few months ago I was convinced I had a problem with black tank ventilation as my bathroom smelled to high heaven. Turned out to be a dead rodent under the vanity. I never thought I could confuse the two smells, but I did.

Just something to consider.

Is it a 36F as you say or a 35F because what you are describing is the 35F layout. Either way at www.winnebagoind.com you will find the complete plumbing schematic.

As an owner or a 35F, I have, on occasion, noticed a slight sewer odor in that compartment. It is never strong enough that I have had to investigate aside from checking the hose connections. The half bath toilet sits directly atop the black tank. If you have the same setup there is a dump valve, macerator pump and tank in the compartment.

Check for an air admittance valve under the sink. Maybe have it's bad.

blknomad wrote:
I have an Itasca 36F that has 2 bath rooms. Love the floor plan but I have a problem. The small mid coach bath room has a terrible odor as does the compartment below where the black tank pump is located. I have used plenty of the black tank deodorant pills, lots of water, flush it often, checked all fittings and clamps and still have terrible smell. Could this be a vent problem? Has anyone else had this problem?

Do you use the sink regularly or has the MH sat for awhile?
The p-trap in the sink could have evaporated. This happened to me a couple of times especially when in warm weather states. My sink dumps into black.

One time on my MH the sewer smell coming in was from VERY tiny hairline cracks around the screws that hold the valve blades on. Couldn't believe such a minute leak could cause odors.