Sewer smell in the kitchen

[flyboy]

I have an `04 Mandalay diesel pusher that smells of sewer when I turn on the overhead fantasic fan. The smell is coming from under the kitchen sink. I have replaced the screw-in vent under the sink, and I filled the black and gray holding tanks with smoke looking for leaks but none were found. Does anyone have any suggestions that I might try? Thanks!!!!!

[garykd]

Hi Flyboy,

Welcome to the FMCA forum. Is the trap in the sink drain full of water?

[flyboy]

Hi Gary,

Yes the trap is full. After dumping the holding tanks, I always run water in all 3 sinks to make sure the traps are full.

[tbutler]

You have an '04 coach, is this a new to you coach or have you had it since new and the problem is something which is just now occurring? Do you live where there are hard freeze temperatures in the winter? Could a drain pipe possibly have been split by freezing water? You may not see a huge cloud of smoke coming from a source, it doesn't take much sewer gas to create a big smell. Our noses are very sensitive to such odors.

Beyond the kitchen sink, I would check the washer/drier drain (if you have one or if the coach is plumbed for one). Sometimes you can think a smell is originating from one place when in fact it is coming from another. Louise swore the washer/drier drain was dry one time and no amount of water would stop the smell. Turned out it was the shower drain that was dry. A little water and the problem was solved.

Another thing to check would be to make sure the vent stack to the roof has not separated or been cracked. A vent fan creates negative pressure in the coach and any source of leak will be drawn toward the fan in the kitchen.

Finally, if there is a leak in the sink plumbing, you might have some moisture and/or mold under the sink that is creating the smell. Check below the cabinet floor to see if everything is dry and in good condition.

That about covers all the possibilities I can think of. Good luck finding your problem!

[garykd]

I know you mentioned you replaced the screw on vent. However, it is a cheap plastic part. Consider making sure it is working correctly. All other things being equal and no disasters (i.e., cracked drain pipe) waiting to be discovered that is about all I can suggest. As a long shot, there should be another drain vent in another sink. The aroma you are sensing is most likely coming from the grey tank. The grey tank can smell almost as bad as the black tank. If you find another drain vent, try swapping it with the vent in the kitchen drain.

[phranc]

A " quick and dirty" fix , is to put a sandwich bag over the plastic vent and rubber band it in place. Just for testing purposes to see if smell goes away.

[thomasp]

We had that problem with a 2003 Winnebago Brave. Tried several remedies but nothing would keep the smell from forming, particularly in hot weather. We did however find a way to mask it. There is a liquid made for RV grey water tanks/sink odors that you put in the drains which controls the smell. We bought it at WalMart and it works really well.