I have an issue with sewer smell inside my RV. I have done as others suggested and replaced the air admittance valves under my kitchen sink, and under my bathroom sink. I still have the sewer smell. The smell WILL stop if I close the grey water valve to the RV. I would like the luxury of leaving the grey water valve open, so I don't have to empty it often, as I am full time living in my RV.Any suggestions?

I may have this wrong, but if you leave your gray water tank drain valve open, hooked up to the sewer hub and therefore empty, you are inviting the fumes from the park sewer system to back up into your tank & sink drain if you do not have a trap in it, if the trap is not filled with water or if it is working improperly. I leave all drains closed and dump intermittently. Gray water is a good flush of the sewer hose after dumping black water.

one_strange_texan wrote:I may have this wrong, but if you leave your gray water tank drain valve open, hooked up to the sewer hub and therefore empty, you are inviting the fumes from the park sewer system to back up into your tank & sink drain if you do not have a trap in it, if the trap is not filled with water or if it is working improperly. I leave all drains closed and dump intermittently. Gray water is a good flush of the sewer hose after dumping black water.In my opinion this is spot-on.

one_strange_texan wrote:I may have this wrong, but if you leave your gray water tank drain valve open, hooked up to the sewer hub and therefore empty, you are inviting the fumes from the park sewer system to back up into your tank & sink drain if you do not have a trap in it, if the trap is not filled with water or if it is working improperly. I leave all drains closed and dump intermittently. Gray water is a good flush of the sewer hose after dumping black water.If there is a problem with the traps, the OP should still get the fumes from the gray tank when the valve is closed?I agree, I also keep the black and gray valves closed until they need dumped.Maybe a different/better air admittance valve will help?If possible, temporarily rubber band a plastic bag over the air admittance valves and open the gray tank valve. See if it makes a difference. Just because the air valve is new, it doesn't mean it is working properly.Make sure the traps are filled and holding water before you check the air admittance valves.

We learned early in our camping experience to keep the valve closed, and open only to empty. Otherwise smells do come up through the sinks. No reason to leave them open anyway, you want both tanks to be filled when emptied so you have a force of water flushing everything out.

Do you have a washer/dryer prep in your RV? A lot of times people overlook keeping that trap full if it is unused.

Sewer smell inside RV....Help needed.... | Good Sam Community

one_strange_tex
Explorer
Aug 10, 2016
I may have this wrong, but if you leave your gray water tank drain valve open, hooked up to the sewer hub and therefore empty, you are inviting the fumes from the park sewer system to back up into your tank & sink drain if you do not have a trap in it, if the trap is not filled with water or if it is working improperly. I leave all drains closed and dump intermittently. Gray water is a good flush of the sewer hose after dumping black water.
WeBeFulltimers
Explorer
Aug 10, 2016
one_strange_texan wrote:
I may have this wrong, but if you leave your gray water tank drain valve open, hooked up to the sewer hub and therefore empty, you are inviting the fumes from the park sewer system to back up into your tank & sink drain if you do not have a trap in it, if the trap is not filled with water or if it is working improperly. I leave all drains closed and dump intermittently. Gray water is a good flush of the sewer hose after dumping black water.

In my opinion this is spot-on.
gbopp
Explorer
Aug 10, 2016
one_strange_texan wrote:
I may have this wrong, but if you leave your gray water tank drain valve open, hooked up to the sewer hub and therefore empty, you are inviting the fumes from the park sewer system to back up into your tank & sink drain if you do not have a trap in it, if the trap is not filled with water or if it is working improperly. I leave all drains closed and dump intermittently. Gray water is a good flush of the sewer hose after dumping black water.

If there is a problem with the traps, the OP should still get the fumes from the gray tank when the valve is closed?

I agree, I also keep the black and gray valves closed until they need dumped.
Maybe a different/better air admittance valve will help?
If possible, temporarily rubber band a plastic bag over the air admittance valves and open the gray tank valve. See if it makes a difference. Just because the air valve is new, it doesn't mean it is working properly.
Make sure the traps are filled and holding water before you check the air admittance valves.
pennysmom09
Explorer
Aug 10, 2016
We learned early in our camping experience to keep the valve closed, and open only to empty. Otherwise smells do come up through the sinks. No reason to leave them open anyway, you want both tanks to be filled when emptied so you have a force of water flushing everything out.
schlep1967
Nomad
Aug 10, 2016
Do you have a washer/dryer prep in your RV? A lot of times people overlook keeping that trap full if it is unused.
jwireman89
Explorer
Aug 10, 2016
If you are using a slinky sewer hose, you might try making a trap by letting the hose slump down in a U shape on the way to the hookup.
tropical_ron
Explorer
Aug 10, 2016
Jwireman89 has a great suggestion. I have found that some campground sewer systems siphon the drainwater from traps. I think making a loop drop of sewer hose could help minimize the siphoning. We experience the dreaded sewer odor probably once a year. Closing off grey valve always corrects. Often just running water in all drains eleviates issue. Because this happens randomly and we haven't changed our practices I attribute the occurances to campground drain systems sucking our drains dry.
Coach-man
Explorer
Aug 10, 2016
You posted this same topic on Face Book and were given the same answer, close your grey tank valve, as well as your black tank! Problem solved, oh but you might have to go out every couple of days and drain the tanks? Don't try and take short cuts.
rockhillmanor
Explorer
Aug 10, 2016
Coach-man wrote:
You posted this same topic on Face Book and were given the same answer, close your grey tank valve, as well as your black tank! Problem solved, oh but you might have to go out every couple of days and drain the tanks? Don't try and take short cuts.

X2
Black AND Gray tank valves closed all the time and only opened when dumping. When parked with full hookups it takes all of 2 minutes to go out and pull 2 valves.

Leaving that gray open allows all the grease, food stuffs, soap scum raw chicken juice, etc to harden and stick to the bottom of your tank AND "stink"!
And now no amount of plain water will get it completely off the bottom. The tank NEEDS water in it to prevent that from happening.

Since you left that valve open all this time all that stuff is glued to the bottom of your tank.

The stink from a gray tank smells just as bad as sewer gas and will fill up your RV.

Get a quart bottle of lemon cleaner from the store and pour it down into your gray tank with a full tank of water added and let it sit for awhile and then dump. Repeat if necessary. AND then keep those valves closed. :C
RoyB
Explorer II
Aug 10, 2016
Your exhaust fans and windows etc will pull all of those smells into the RV. The exhaust fan in the bathroom is great for doing this...

Like everyone says its best to leave the gray tank alone until you dump. The gray tank flush being mostly liquid is what really cleans out everything once the black tank has dumped. Always dump the GRAY tank last...

You don't want all of that to build up in your tanks - needs to be flushed out...

Just some of my thoughts...

Roy Ken