Smell - Pipe Air Vents

thanks tkcas01, i will look for them there.

They are called autovents. You can get them at Home Depot and most hardware stores.

http://www.doitbest.com/Drain+fittings-Jones+Stephens+Corp-model-P21-150-doitbest-sku-434792.dib

swamp man, what are those vents called when you order the parts? i looked on camping world and can't find them anywhere, all that comes up is the roof vents. this is my problem in our new to us fiver also. thanks.

Sounds like one of your one way drain vent valves is stuck. They are by each sink and look like a short section of pipe with slots around the device. They allow air into the pipe as water runs through it. If it sticks in the open position you get the sewer smell.

Last summer I had a terrible smell whenever the AC was running for awhile. Over the off season I replaced the vents (air valves) connected to the plumbing under the sinks and this year after several weeks of AC usage...no more smell.

One thing I do is after dumping the tanks make sure to run some water into each drain. Seems the suction of 30 gallons of water draining through a 2" to 4" pipe will suck the water out of the traps. Really not much you can do about it other than refilling the traps afterword.

Thanks for all the replys. I think the below may be my problem....
"sealed that gap between the OD of the vent tube and the roof".

As I remember when I took the roof vent caps off that there was a gap. I will be sealing those gaps and see if that solves my problem.

If you let the tanks get dry, or if they start to get full, they will often smell. Keeping a small amount of liquid in each tank with vinegar or your favorite tank chemical will keep the smell down.

2005 GMC Sierra 2500HD Ext. Cab 4x4 6.0
1998 Jayco Designer 2930RKS

wildbyon wrote:
We had that terrible sewer smell in our 5w this past weekend. Seemed to be strong in the stairway going up to the bedroom. It wasn't there all the time. So, I'm checking all the vents out...all open to the roof; so far only found one of the air intake vents under the kitchen sink to be replaced. Does each sink or tank or toilet have one of these or is there only one in the plumbing system?

. I had the exact problem. I removed all of my roof vent caps (3) and sealed that gap between the OD of the vent tube and the roof, replaced the vent tube covers. No odor now in 18 months full timing.

In my Montana there were two of the ones called air admittance valves. One for each sink trap in the bathroom and kitchen. They were both bad from the factory. Replaced both and problem went away. If you have any more sinks than that there most likely is one at that location also. It is cheaper in the manufacturing process to install these than run a vent through the roof. Code requires a vent for every trap within 6 feet if the manufacturer follows it.