Aneurysm, water fall and .... plumbing!
According to wikipedia an aneurysm is a balloon like bulge in the wall of a blood vessel. Well today I learned that motorhomes (or more precisely Global Expedition Vehicles) can also suffer from aneurysms; and the bursting of one particular aneurysm turned our motorhome into a good imitation of a water fall. Specifically 50 gallons of water washed through the camper and flowed down the entrance steps in a beautiful, though frightening, cascade.
So what happened?
Well is seems that in the bathroom of our GXV Safari the last 2 feet of the plumbing that runs to the shower water mixer control is a soft flexible plastic tube (the flexibility aids the installation of the bathroom as that part of the camper is very space limited). But unfortunately the tubing that was installed in our camper was not rated for use with hot water and over time the hot shower water caused the tube to expand (that is form a balloon or aneurysm) which chose the afternoon of Feb 5th to burst.
What next!!
The first step - turn off the pump - that at least stopped the flow of new water.
Then; as you can imagine 50 gallons of water can cause a bit of a mess and so we spent some time mopping up water, tossing out mats and generally trying to get things to dry; but we are now back in Gig Harbor WA and getting things to dry is not a strong point of the Feb weather in Washington.
Diagnosis
But quickly the big question became where is the leak and how do we fix it.
It was obvious that the water was leaking from behind the bathroom cabinet but without access to the back of the cabinet no further action was possible.
Hence cut a hole in the back of the cabinet to get access to the plumbing. This was achieved by drilling a series of holes and using a Dremel tool to join up the holes - voila: we now had an access panel. Pity the builders did not think to provide access to the plumbing!
I repeated this process a few times extending the panel upwards but was not able to expose the leak.
Dismantle the cabinet
So now I faced the inevitable and started to dismantle the top part of the bathroom cabinet. This was a lengthy process and was accompanied by some cursing of the builders who obviously had given no thought to any possibility that some form of repair or maintenance may require the cabinet to be disassembled or removed. In the end I had to resort to brute force on one screw that was clearly put in place before the bathroom window was installed; and now with the window in place was completely inaccessible.
Once the top part of the cabinet (above the counter top) was out the problem was evident; a ruptured plastic pipe.
The repair
On the phone with GXV I was told that I needed to find some plastic tube to replace the failed piece. This tube would run from the PEX barb on the shower mixer to the PEX tubing lower down in the plumbing. Specifically I was told to get some braided plastic tube; with a 150 F° temperature rating; 250psi pressure rating; 0.5 inch internal diameter; and OH! by the way it had to be thin enough (that is have a small enough outside diameter) that a PEX clamp would fit around it.
This sounded like a poor solution to me. Why should I go looking for a special piece of plastic tubing when a more standard solution can be seen in my own kitchen (and in the camper's kitchen and on the campers bathroom sink).
My solution can be seen in the accompanying photos.
Run some PEX tubing from the shower mixer down to just above the level of the counter top and terminate that PEX run with a 3/4 male threaded pipe fitting (fitting available at Lowes).
Run some PEX up from the floor to about 24 inches below the counter top and terminate that run with another 3/4 inch threaded male pipe fitting.
Join the two PEX assemblies with a 24 inch stainless steel braided line (with a 3/4 female pipe fitting on each end) available at any Lowes or Home Depot.
In the 4th of the photos above the ends of the silver braided lines can just be seen in the background coming down from behind the cabinet rear wall. The silver braided lines in the foreground were installed by GXV to supply the faucet in the bathroom basin (why not do the same with the shower?).
Had this solution been used during construction the problem would not have happened in the first place.
Why use the plastic tube rather than my solution (or some other more common solution) - I don't know.
Fixing a problem before it happens
While delving beneath the bathroom cabinet I noticed that the cabinet floor was resting on and putting pressure on the hot and cold water pipes as they emerge from beneath the shower pan floor. So as you can see in the second of the following two photos I removed a piece of the cabinet floor and adjoining wall to relieve that pressure. The red and blue PEX are now unobstructed where they emerge from the "clam-shells"
