Bad oder after drain holding tank

[Bill&Dot Teske]

I have a very bad oder after we drop the Fresh water tank (seems to be coming from shower) I have a 2001 Itasca suncruiser 38' We are third owner ,it does look like some new plumbing under shower.Can the oder come from grey water holding tank WHAT CAN I DO.

 

[mnmnutswer]

I had an oder also in my gray tank. I put some bleach in the tank. Filled with water and let it sit a few hours then drained....Order all gone...

 

[John Canfield]

A common cause of odors is a loss of water in the sink traps.  Run some water in all of the sinks, air out the rig and see what you get.

 

[Bill&Dot Teske]

Thanks ,Sounds Good I'll try that ,Thanks Bill

 

[Clay L]

Another common issue is the air admittance valve under the sink.
When you dump it opens to  let air into the drain pipe to prevent water from being sucked out of the trap. If it doesn't close all the way afterwards you will get gray tank odor. It is found on a stub off of the drain pipe after the trap and can be unscrewed and replaced easily.
New ones can be found at hardware stores. Prices range from $5 or $6 to $30 or so depending on quality.

 

[hdmox]

Another common problem is with the 1-1/2? vent caps that are on top of the vertical black plastic pipe that your P-trap feeds into.  In my ?04 Suncruiser there are 3 of these, one under the galley sink, one behind the washer/dryer, and one under the bathroom sink for the sink and shower drains.  They allow cabin air to flow into the gray tank when you pull the dump valve, which creates suction on the gray water drain lines.  When not dumping or otherwise having negative pressure in the lines, they are supposed to close tight and keep tank odors from coming into the coach.  They are essentially a one-way path or check valve between the air in the cabin and the air in the lines above the gray tank.  If they stick, hold your nose?often the gray smells worse than the black!

They are available through your local or online WI dealer, but can be purchased at your local home improvement store for about $6.  Make sure you get one with a positive spring action on the vent, like this. It just screws on.

 

[jc2]

http://www.lowes.com/pd_24372-143-85539K_0__?productId=1069119&Ntt=plumbing+vents&pl=1&currentURL=%2Fpl__0__s%3FNtt%3Dplumbing%2Bvents&facetInfo=