Water leak under bathroom sink

[rbsheba]

Originally Posted by Rustic Eagle

Sometimes the black tank flush "vacuum breaker valve" is located under sinks and are prone to leak when in use.

The valve looks similar to this:



Bob

Rustic Eagle. I currently have this problem with my black tank flush valve and/or hose . Have towed my TT to the dealership twice to repair the problem since I am under warranty. The problem still exists. How did you fix this? Tired of taking it to the dealer and my current fix is having a bowl under my sink.

[Rustic Eagle]

Originally Posted by rbsheba

snip...... How did you fix this?.......snip

As a temporary fix I installed a plastic elbow in place of the twice leaking cheap OEM plastic vacuum breaker and use a 3/4" brass vacuum breaker that I connect on the outside hose/TT flush connection. Works great, accomplishes the same protection as the cheap 90 degree valve.

I plan to purchase a 90 degree "brass" vacuum breaker in the future...., much more reliable than the cheap OEM plastic ones.

Plastic elbow & couple threaded adapters........



3/4" hose vacuum breaker (Lowes)........



Bob

[Hdickin580]

I’m having this same problem in my 2018 29RKS. I have an appointment to bring it back to the dealership next weekend to have it fixed under warranty. Will let you know what they find. Heather

[jdgmint]

If your rig has a canister water filter under the sink (as our does), check the canister " o-ring".

[TnHiker]

Had a leak under the kitchen sink on my 2018, the fitting that transition from PEX to the fixture were just hand tight. Later the same thing on my water heater fittings as they were also loose. Good luck.

[McJayke]

We have a similar problem when we failed to use the pressure regulator at a campground last summer. Just a trickle that ended up in a puddle between the bathroom cabinet and the shower. I did since up the nuts connecting the PEX connected to the spigot. No problems since. Didn't have a regulator with a pressure gauge.


Our 5th wheel was used when we bought it several years ago and there is evidence (slight swollen wood) on the bottom of the cabinet where it must have happened before.

[DNelson]

Like many we also had a plumbing leak under the kitchen sink. It was periodic and all fittings seemed tight. I wrapped a paper towel around each connection and put a piece of duck tape around them to keep them in place. Turned out to be the hot water connection. The problem in many instances is that Jayco (and probably many manufacturers) directly connects the PEX to the faucets which practically guarantees a leak somewhere at some point in time. The PEX should connect to a flexible hose and the flexible hose to the faucets like every home has. The manufacturers don't want to spend the few bucks to purchase and install flexible hoses!

Good luck!

[travelingjw]

If the suggestions above don't work, one more "investigative" suggestion. Over the years when searching for difficult to find leaks I have learned to have DW run water, all open (at another sink) then "slam" the valve shut to try and create pressure throughout the system. Also, shut water on and off as fast as possible if first suggestions doesn't work. Sometimes the quick change in pressure will force the water out of the leak.

[Mustang65]

Not sure where your black-water tank one-way-valve is, but I had a leak under the bathroom sink. Laid paper towels all over, wrapped the pipes in paper towels..... Each day... nothing, until Thursday, the day I dump the tanks and use the city water to flush out the black tank. Low and behold, spots of water on the floor paper towel. The water was coming from the Black tank's one way valve. The water connection was on the outside wall and came in through the bathroom sink cabinet. I used electrical tape to temporarily stop the leak until I got a new valve. Well, that was 3 years ago and I still have not purchased a new valve and I still do not have any water dripping. Maybe this summer, if I remember.
Don
My Registry

RVing with SOLAR

[rbsheba]

Read my manual. States not to keep flush hose attached to trailer when not in use. Problem solved as long as I have the hose attached tightly when in use.