3791RD Water Leak

[wecker1]

DW noticed water dripping ever so slowly outside and below the doors to the battery compartment in the nose of the RV. When I loosen the screws that retain the molding in that area the water drips faster for 15-seconds or so and then stops. After several hours water will begin dripping again. We do have a splendede washer/dryer combo in the bedroom closet (RV nose) which is above and forward of the leak. I ran the washer and checked for leaks both during the wash/rinse cycle, and the drain cycle. No visible leaks, no moisture on the water or drain lines, and no water in the drain pan. Looking through the cut-out in the wall behind the washer I can see that the insulation below the washer in the nose of the RV at the very bottom, which is the horizontal section of fiberglass in the nose by the hitch, is wet. Again, only the bottom couple of inches of insulation is wet. The ten or so inches of insulation above the bottom few inches is dry. Based on this observation I think that the water may be coming from elsewhere and pooling here. The bathroom is the next closest water source but I cannot detect a leak there either? A roof leak is not the source as we haven't had rain for almost two weeks. Based on the above info, does anyone have any advice on what the source of the leak may be? Thanks

[DQDick]

If you've used the black tank flush during that time the backflow preventor that's frequently located under the bathroom sink could be your problem. Many of us have replaced or eliminated it.

[Daryles]

I had a missing screw from the vinyl under the hittch pin over hang (bedroom closet). When it rained it would drip out the hole.
Check the decor caulking on the roof along your cap. I had a couple of very small bubbles that were leaking. Once I re caulked the drip stopped.
Remove a screw or two from under here and shove a mop string up into the holes. It will wick the water down the string.
Pictures show the washer plumbing behind the cap. You can also get to this by removing the covering inside the closet, and the dresser, and the covering left and right of the dresser.

[wecker1]

Based on my above stated actions and the fact that I had already replaced the black tank back-flow valve, I believe that the gray tank may have filled during the rinse cycle, and overflowed . The gray tank will remain open during washer use going forward!!

[Tom N OH]

Originally Posted by wecker1

Based on my above stated actions and the fact that I had already replaced the black tank back-flow valve, I believe that the gray tank may have filled during the rinse cycle, and overflowed . The gray tank will remain open during washer use going forward!!

Ouch! Lessons learned...

[Mikelff]

Originally Posted by wecker1

Based on my above stated actions and the fact that I had already replaced the black tank back-flow valve, I believe that the gray tank may have filled during the rinse cycle, and overflowed . The gray tank will remain open during washer use going forward!!

Make sure to form a P trap in your sewer hose when you leave your grey tank valve open. This will prevent sewer gasses (stinky!)from entering your rig through the sewer hose.

[Scootsk]

Originally Posted by Mikelff

Make sure to form a P trap in your sewer hose when you leave your grey tank valve open. This will prevent sewer gasses (stinky!)from entering your rig through the sewer hose.

Wouldn’t the trap for each of the plumbing fixtures take care of that? I have my Montana as a seasonal most of the year with the grey water valves open, never experienced any smell. I close them during travel and a few days prior to my flushing the black tank.

[rohrmann]

The problem is not the individual fixtures but is the tanks themselves. When you have a valve open, sewer gases enter the tanks from the park's sewer system and will exit out the vent pipes at the roof and then can get into the rig through open ceiling vents or open windows or doors. When walking around an RV park, it is quite obvious where the rigs are that have their valves open.

[Mikelff]

Originally Posted by rohrmann

The problem is not the individual fixtures but is the tanks themselves. When you have a valve open, sewer gases enter the tanks from the park's sewer system and will exit out the vent pipes at the roof and then can get into the rig through open ceiling vents or open windows or doors. When walking around an RV park, it is quite obvious where the rigs are that have their valves open.

Exactly true. Making a P trap in your sewer hose is super easy and good insurance against those stinky sewer gasses.

[DebNJim B]

And as a bonus, the P trap in the hose also shuts off an open path into your rig for critters or insects.