sewer odor using whole house fan

[3snowbird]

When using the whole house fan (automatic) over a period of time, I get a sewer odor. I noticed that the kitchen sink vents under the island sink, are any other vents that do not go out the roof?

[Ken / Claudia]

Get up to or on the roof, you should have at least 1 black tank roof vent. It is common to have a fan pulling black tank odors back into the trailer. With the current TT I have, if the bath vent is fully opened odors can come back into the bathroom as that black tank roof vent is real close.
List the RV model your discussing and it may help with a more direct answer.

[HitFactor]

The vent under the sink allows air in so water runs down the drain. That's very likely a gray water drain. Those can smell, but you can probably tell the difference. You can buy a check valve and install it easily if you want to eliminate it as a source.

If no check valve, you could cap if off temporarily, just to see if the smell stops.

Sometimes I notice black tank smells at other sites while walking the dog, are you pretty sure your rig is the cause of the smell? Maybe check around your site and ensure you are hooked up properly.

[3snowbird]

The odor occurs near the steps going up to the bath and bedroom. No odor in the bath. I am curious if there are any vents in the pass through that do not go all the way to the roof?

[notanlines]

Snowbird, so far we know you own a house with a pass-thru. Ken asked for the model/make to get started. I know of no RV's that would vent anything into your basement. Laws would not allow such a thing.

[ctbruce]

Greg has a Montana 3160RE.