Holy mother of all stinks

[sleeplightly]

Ok so we have the camper out this weekend (320 bhs) and this morning I was awaken by what may be the "Queen mother of all stinks" it was definitely related to the black tank. The strange part is that it was coming from the extra AC unit in the bedroom. The bathroom had no such oder. I noticed that the roof vent for thr black tank is kinda close to the ac unit. Could the smell be coming from the vent? I have an idea that the vent could be plugged by my arch enemy the dirt dobber causing the tank to "burp" all the gasses at once. I went outside but couldn't smell anything outside. After a few minutes the smell started to subside and things started returning to normal. I dumped everything then flushed again for the second day in a row. I have a DW and 3 daughters so we go through some water. The really stange part. The same thing happened yesterday morning.
Has anyone else ever seen this before?

[outwest]

Was the air really heavy with humidity and real still (no breeze)? I've had stink from the vent pipe come back in at times like that.

[sleeplightly]

Yes we are in OKC and it was pretty still outside with a heavy dew.

[therink]

Are you hooked up to sewer at a site? Gray tank valve open? Sometimes, sewer gasses from campground sewer can travel up your drain hose, into tank and then up and out through roof vent. I've had that happen. I closed tank dump valve and it went away.

[sleeplightly]

Therink
Thanks. I had not thought about it doing that. I will dump all tanks as needed for the remainder of the trip maybe that was the problem.

[Javi]

Therink
Thanks. I had not thought about it doing that. I will dump all tanks as needed for the remainder of the trip maybe that was the problem.

Learned that the same way you did... just several years ago. I never leave the valves open when hooked up to the sewer.

[hankpage]

If you are going to leave the gray valves open, put a block or two under the sewer hose spaced apart to create a trap to prevent the sewer gas from entering the camper. There should not be any intake air on the roof A/C to bring the stink in. It is very possible that a gray tank may not be vented through the roof and you have a cheater vent under one of the cabinets that has gone bad. (common but only about $5 to replace) Good luck and let us know what you find, Hank
http://www.keystonerv.org/forums/picture.php?albumid=251&pictureid=1117

[sleeplightly]

After we dumped and flushed the tanks again we had no more problems. Not sure what the problem was but man that was aweful. Thanks for the helps folks. If the problem persists I will keep looking for the issue.