Originally Posted by RVhiker
This answer assumes that the cutoff valve for your hot water tank is plumbed with 1/2" Pex and stainless steel clamp fittings.
It's not too hard to change out a valve, if you have the proper tools and a bit of knowledge. The tools are a Pex stainless steel clamp crimper and a Dremel tool with a cut off disc. The Dremel tool is used to cut the old stainless steel clamps that hold the valve. Done carefully, this can be done without damage to the pipe. Install the new valve and use the clamp crimper to tighten the clamps.
A stainless steel clamp crimper costs about $50 - $70 and a Dremel tool about the same. Any plumber could easily do this job for you if you don't have the tools and would rather not invest in them. There is a lot of Pex plumbing in my trailer, and I've found the tools come in handy.
Very nice explanation, RVh!
Another option would be to switch to "Shark Bite" fittings. The fittings themselves are about double the price of PEX, but they're all metal (rather than plastic) and you just push
them on. You won't need the crimper or the Dremel - just an $8 PEX/PVC cutting tool and a piece of 1/2" PEX tubing ($4 - $5). Cut the PEX tubing around the fitting, push on a Shark Bite tube x tube splice, T, elbow, or whatever you need, cut a short piece of PEX to make up for the length you cut off, push on the Shark Bite valve, and your done!
I do quite a bit of plumbing work on manufactured homes (which also use PEX tubing), and I've had great luck with them.