Sorry..hit "send" too soon.
When my wife uses the shower when we are dry camping, not hooked up to sewer, the drain gurgles a LOT. You can even see the water bubbling up toward the bottom of the kitchen sink. This never happens when we are hooked up to sewer, and it only happens after the 2nd or 3rd shower.
Could this be a vent issue? If so...how do I check on it? It's a mystery to me that it only happens when we are dry camped.