Where is my water leak? I have a feeling someone knows.

[JShort880]

Hey Everyone,

Hope everyone had a Great Christmas. Wondering if anyone has any insight on the following (currently in troubleshooting mode).

Problem: Random water leaking from:

1) Underneath kitchen sink toward toy hauler door
2) Adjacent wall in the back bathroom.

It's not any of the water lines. I've took the back wall off (inside of my back bathroom that has the kitchen sink behind it) and ran water from everywhere with no leaks.

This wall holds the two 1 1/2-inch non-pressure pipes that I'm assuming connect to my back 2 AC units.

I'm running them one at a time now (even though it's 35 degrees in Georgia) to see if I can get some water. But I figured someone else has experienced this and can catch me before I head in the wrong direction.

Sidenote: Do I really need two bathrooms? Really thinking about how nice it would be to push the cabinets/sink into that spot (Might not be structurally possible, have not checked).

[NH_Bulldog]

The non-pressure pipes are not related to the AC units. Condensate from the AC units simply flows across the roof surface to either side and then into the gutters and then drips onto the ground at any of the 4 corners.

The pipes you see are tank vent pipes, one for the black tank and the other for the grey tank. If you haven’t already done so, I would suggest getting on the roof and inspecting the caps and roof sealant around the vents and any other roof penetrations (roof vents, attic vents, skylights, etc.) within 8 feet, since water can travel a good distance.

The only way for those pipes to leak water is if they back-filled with water from the holding tanks, but you would have had water erupting from the toilet and sink at the same time.

[JShort880]

Originally Posted by NH_Bulldog

The non-pressure pipes are not related to the AC units. Condensate from the AC units simply flows across the roof surface to either side and then into the gutters and then drips onto the ground at any of the 4 corners.

The pipes you see are tank vent pipes, one for the black tank and the other for the grey tank. If you haven’t already done so, I would suggest getting on the roof and inspecting the caps and roof sealant around the vents and any other roof penetrations (roof vents, attic vents, skylights, etc.) within 8 feet, since water can travel a good distance.

The only way for those pipes to leak water is if they back-filled with water from the holding tanks, but you would have had water erupting from the toilet and sink at the same time.

Makes sense.

It is coming from the rear AC. I ran it for about 20 minutes and that water first lands on the floor underneath the rear bathroom sink. It is time for everything to be resealed so I'm going to wait for a warmer day to tackle that one.

Thanks

[chuckster57]

If you have ceiling assemblies for the AC’s take them down and look for the four corner bolts that hold the roof unit are tight. Domestic states 40 inch pounds for bolt torque. I personally think that’s difficult. You want the gasket compressed to roughly 1/2 its original thickness. It’s not uncommon for that seal to compress over time. DO NOT use and sealants on that seal.

[JShort880]

Originally Posted by chuckster57

If you have ceiling assemblies for the AC’s take them down and look for the four corner bolts that hold the roof unit are tight. Domestic states 40 inch pounds for bolt torque. I personally think that’s difficult. You want the gasket compressed to roughly 1/2 its original thickness. It’s not uncommon for that seal to compress over time. DO NOT use and sealants on that seal.

Thanks Chuck. Just went and read into that a bit and I wouldn't be surprised if that's exactly what is going on.

Edit: In case someone else had this issue and stumbles on this thread.

https://www.youtube.com/watch?v=suXObXYCmpY

[Martian]

If the leak is coming from the bathroom wall it could be the black tank flush line that is usually located under the bathroom sink.

[Strwbry]

Hello,
I might be having a similar situation. Going thru threads did I realize after checking 5 times have found it. The problem is I don’t know how to open it ugh. I tried to turn the black nob looking thing but it wont move and I don’t want to push and pull to much unless I know what it is. I couldn’t attach a picture, sorry.
2015 Passport Utra Lite 2200RB

[chuckster57]

Originally Posted by Strwbry

Hello,
I might be having a similar situation. Going thru threads did I realize after checking 5 times have found it. The problem is I don’t know how to open it ugh. I tried to turn the black nob looking thing but it wont move and I don’t want to push and pull to much unless I know what it is. I couldn’t attach a picture, sorry.
2015 Passport Utra Lite 2200RB

If it’s the black tank rinser anti siphon valve that’s leaking, they are not made to be taken apart. Simply replace with a new one or remove it, join the two pex lines together and use an anti siphon valve at the exterior connection.