ATF: MPG - Question regarding p traps and gray tank odor

[sjones]

I've owned my MPG 183 for 14 months. Month 12, 4th use, a foul sulphur odor started emitting from the sink drains. I was told by the vendor that I needed to put chemicals in the gray water tank. I am doing so, and it has helped. I'm also flushing the fresh water/gray water tanks repeatedly to try to clean it out. When I read the manual there is a mention of the p-traps being in place to prevent odor from coming up. Is there a chance that the p-traps are not working? How would that be determined?

 

[Ray LeTourneau]

sjones, the "P-traps" are exactly like the ones in your home and normally don't malfunction. What happens sometimes? There should be a vent under the kitchen sink cabinet that has a screwed on check valve. It's supposed to let air into your gray tank. Sometimes this valve is loose or it may have come off. This would then allow tank gases into the coach. Look under the sink cabinet for a black 1-1/2 inch pipe coming up through the floor and not connected to anything. There should be a screw on fitting on the top of it. Make sure it's hand tight. You can check the p-traps but as long as you don't have a broken sink drain I doubt there is anything wrong with them.

 

[DougS]

What Ray said. Sometimes the seal inside of fitting let's tank air out. I have had two of them go in my last units over the years. This is a common plumbing fitting and can be bought in one of the big box stores.

 

[jpdoggett]

If your RV sets for a long time with not being used the water can evaporate out of the p trap have had this happen

 

[Bob&Patty]

If your "P" traps dry up (no water in them) you will get a smell. If it sets for long periods of time, pour a bucket of water in all the sinks and toilet. We use dawn soap in all our sinks. Put some water and dawn in the kitchen sink after you drain it. Its keeps the solids and grease loose in the tank.

 

[Tumblebug]

The grey water line from tank to sink was mis aligned On My MPG 183, and leaked, some fittings cracked, it was not correctly installed. Dealer made the repair and have no problem now. Your problem could be from p-trap to tank check those for cracks or breaks.