Sewer smell when draining kitchen sink

[JohnDar]

I keep all three of my tank valves closed until they need to be dumped. Usually that is dictated by the black tank. The only time I leave the Gray #1 valve open is when we're running the washer.

In regards to the black tank "bubble," that's a sign (normally) that the tank ain't gonna take another visitor. After some "experience," you can tell from the sound of the flush when the tank is getting almost ready to start belching. The sound of the water going down takes on a deeper tone, almost a "vaawoomp." It's probably a couple of gallons from being full.

 

[wsenecal]

Thanks for all the ideas- Some updates-

1. You guys were right on the black tank- water pressure was too low due to regulator having junk in it. "Stuff" wasn't making it all the way down. Was able to clear it and getting new regulator now. Tank also flushes fine.

2. Regarding drain valves being open when hooked up to septic- I had been leaving the kitchen grey water tank valve open so I didn't have to deal with it. However, any odor from the septic tank up through is noticed IMMEDIATELY when standing by the door. I've since closed the drain valves and will watch for the odor. Any thoughts or best practices for folks who have their unit parked on some property and hooked up to a septic full time would be greatly appreciated.

3. I'm convinced now (although haven't climbed onto roof to check yet) that both vent pipes are not making it through the roof. Saw comments from several folks noting this, and I notice the smell now when someone takes a shower and the front AC unit is on. I'm headed to camping world now to buy 2 cyclone vents and deal with whatever else I find up there. Will report back tomorrow as it's 100 degrees in the shade right now.

Thanks again for all the comments. This is a great forum and I've found a lot of good ideas here.

 

[wsenecal]

Bought new high-flow water regulator and was able to get toilet to flush properly and dump/flush blank tank without issue. Put a few gallons of water in there per previous suggestion and will watch. Bought 2 cyclone vents (need 3 though) and went up on roof to see what was going on with existing camco vents. Turns out the pipes are sticking through right to the bottom of the outlet of the existing vent. However, they never sealed between pipe and roofing material. There are some very small gaps where I could see air getting sucked in. I also had my wife run toilet, bathroom sink and kitchen sink while I had the caps off the existing pipes. While the largest amount of vapor came from the black tank when she flushed the toilet; the force of the odor from anyone of them didn't seem strong enough to be raising the smell that greeted when I went back inside. The AAV's under the kitchen and bathroom sinks aren't giving off any odor at all, so I'm still at a loss as to what could be going on. Does the vent pipe run separately back to the tank or is it simply T-d off the sink drains?