I finally got around to changing out the 3 way ball valve in the water bay that has been broke for about 9 months. A lot of that time was spent trying to source an identical valve with the same mounting holes at the Tiffin supplied one. The only company that had a matching valve was Apollo. I ordered one but when it arrived it had a plainly marked label indicating that it was not for use with potable water.
Even on the Tiffin store site they now show a replacement valve with “Midland” marked on the handle for about $60. I checked the Midland web site and their site also stated that their 3 way valve was not to be used for potable water as well. If Tiffin had special valves made just for them I can't say, but I didn't want to take the chance.
I sourced a near identical lead free valve on Amazon for $25. The difference was that it didn't have the mounting holes that the first one did. https://www.amazon.com/gp/product/B07BB
As expected the biggest hurdle in replacing the old valve was getting to it. I figured out a way to access the valve with only minor disassembly of the water bay. To access the valve I removed an upper section of face panel about 14” long on the right side of the panel. It was held in with 3 screws. From there I could see behind the panel, and the use of a mirror and flashlight helped a lot. I was thinking that I would try to pull the valve up high enough to access the 3 Pex lines on the back of the valve and cut off the Pex bands. But the other lines attached to it were not long enough to allow me to pull it up above far enough to work on it.
A little more investigation showed that if I unscrewed the cold water supply to the back of the outside faucet and then unbolted and removed the hose reel and lift it out of the bay it made a good sized access point and I could pull the water valve down and to the right just far enough to access all of the existing Pex lines.
The existing Pex lines that ran off of the valve was the center lines was the incoming water line from the hose reel, the right side line ran to the fresh water tank, and the left side line was the city water feed line. The line to the fresh tank was plumbed with a piece of flexible hose that made it easier to pull the valve over to the opening.
From there it was fairly easy. I used a Dremel with a cut off wheel to cut through the pex bands which are copper and cut easily. To help getting the pex lines free of the valve I used a heat gun to warm them a bit. I was going to try to reuse the existing lines, but the pex pipe is so cheap ($1.86 for 5' at HD) I just cut new pieces and reduced the chance for any drips later.
Putting the new valve in same orientation as the old valve keeps the function just the same, so the matching “tank fill” and “city water” positions are the same. To mount the new valve I used a short length of plumbers metal strapping tape (about 4”) and formed it around the outside of the left outlet on the water valve. A short piece of duct tape wrapped around the outlet first made a firm place for the strapping tape to cling to during the reinstall. An extra short piece of duct tape on the back of the strap also kept it from sliding off during the install.
Two short bolts and nylock nuts inserted from the back of the panel through the holes in the strap secured the new valve solidly to the panel. A screwdriver from the back held the bolts while tightening the nuts. Removing the yellow handle also makes inserting the new valve easier.
The preliminary test was perfect, and now the valve services the fresh tank and city water supply once again. I cleaned up the bay a bit and reattached the removed parts.