Our 2014 3570RS has grey water smell coming up from the utility cabinet area. Especially after doing dishes a couple times. Every time. I dropped the insulation cover on the bottom and there are no signs of leaks. Just strong fumes coming in. Once tank is drained, no more smells until I do dishes a couple times. Grey water tank is not full. Could it be the anti-siphone valve? What's confusing is this RV has the center island counter and sink also where the anti-siphon valve (no smell there) but the smell comes into the cabin area up thru the shaft behind the light and elect panels thru the drawers in that cabinet. Thanks for your help.
Grey Water smell in utility cabinet when dumping
- Thread starter Boozecamp
- Start date
JohnDar
Prolifically Gabby Member
There isn't an anti-siphon valve on the gray tanks, or the black tank for that matter. The ASV is on the flush line for the black tank. There are, however, Stoddard valves on the gray tanks (aka., air admittance valves) that open when water is draining to the tank. If they stick open, you can get tank odors.
Look inside the cabinet for a vertical pipe with a slotted cap on top. Unscrew the cap and clean the rubber valve and make sure it's still flexible.
Sent from my iPhone using Tapatalk
Stoddard valve appears to be ok under sink. Puzzling
JohnDar
Prolifically Gabby Member
Other possibilities are the vent on the roof is blocked or there is a leak at the point where the plumbing enters the tank on top. Unless you overfill the tank, you won't get a water leak, but you might get the smell. Gray tanks can smell as bad as the black tank.
One thing I've noticed is that when our rig sits idle for a week or more, I can get "tank" odors even if I've dumped all of them and recharged the black with clean water before we left. Running water into them and dumping again normally gets rid of the smell for the rest of our stay.
You could also try pouring some liquid tank chemical into the sink drains and running water to get it to the tank. Might help digest any decaying food particles lurking down there.
One thing I've noticed is that when our rig sits idle for a week or more, I can get "tank" odors even if I've dumped all of them and recharged the black with clean water before we left. Running water into them and dumping again normally gets rid of the smell for the rest of our stay.
You could also try pouring some liquid tank chemical into the sink drains and running water to get it to the tank. Might help digest any decaying food particles lurking down there.
danemayer
Well-known member
If your gray tank dump valves are open when you get the smell, let your sewer hose sag at the outlet to create another P-Trap - this on on the outside. If the problem goes away, it's sewer odors coming up into your coach. The Studor Air Admittance Valve may appear to be working, but if it's 2 way instead of 1 way, and your gray valves are open, when someone else dumps their tanks, you can get sewer odor.
JohnDar
Prolifically Gabby Member
If your dump valves are always left open, you run the risk of draining the water and leaving a growing pile of rotting food debris behind. Leave gray tanks closed until the tanks need to be dumped. Then dump them after dumping the black. Helps clean the recalcitrant sewer trout that might want to hang out inside the hose.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
Lou_and_Bette
Well-known member
This. Worked for us also!!!
