The smell from the stack vent and air inlet valves in my coach is now fixed. Behind the washer are 1.5" pipes that connect the washer, and also the black and grey tanks to the roof vent. There has been a noticeable odor coming from that area, in the top closet. Below where the washer should be are my lithium batteries, inverter and solar controller. The pipes are behind that so no access there, unless I want to take on a can of worms.... no thanks.
So how to get there?I first cut a hole in the top back end and found a abs pipe running cross wise to the vent to the roof. No way to get past it unless cutting it. Next I looked at the closet next to it, and thought about cutting into that, but I would also have to cut the pipe that comes up from the grey tank for the washer drainage. Next I took off the dryer inlet on the side of the coach. No dice, there is a up pipe next to it connecting the bottom pipe to the top pipe. One for drain, one for venting. I still could not see well inside. Didn't know where the air inlet valves are. Or even if there was one. I mean if your going to put batteries and inverter there, you would get rid of the stuff for the washer, right?
Ah but that would be to simple. And no. That is not what they did.
So I cut across the back top, removing the 1X.5 wood. Now I could see the air inlet valve and it was old. Then cut the cross pipe. Original I believe but don't know for sure. Next to it was.... WHAT??!! Could that be blue painters tape on top of a plumbing connection? WT@.... Yup it was. Covering a copper pipe that was open to the sewer gas. Now I knew where the smell was coming from. Taking off the air valve didn't give me much access to the tape, but graduadly I got it off, and shoved some paper down the pipe, half way then filled with RTU silicone adhesive caulk. Was going to use marine 2 part epoxy putty, but figured the rtu was enough. After filling that, I was going to put in a new air inlet valve, I have 3 but in the end decided on closing it with a plug.
Cementing pvc to abs with the correct cement and I just had to put the top back on. Done.
Just no telling what the mindset was going into the lithium battery install.
Me I would have put it on the top closet. Then you still have the space for the washer, but you could just as easily use it for storage. Some reinforcing of the floor would have been necessary but it would have worked no problem. Don't know why the dryer vent wasn't closed off either. A future job for me. As is closing the refrigerator vent on the roof.
Are there any other drains in the bathroom on that side of the rv, sink or shower? The vent you closed off could be for multiple drains.
Good job getting rid of the oder, not much is worse in a rv.
Jack the sink is vented underneath, and it has a new studor vent. The shower is vented behind toilet, both on opposite side of the coach. Nothing else there but washer.