Yes, I know the pipe is different. Last spring I assembled a summer/winter set of fittings around the water heater. The idea was to make it easy to pull and push a few pieces to disconnect and drain the tank and leave the rest of the fresh water system intact to be winterized. Squirted water all over the place once the VSD pump got up to pressure. Back to the $%@#%! hose clamps.
So this winter have wondered about CPVC and PEX, but it all comes down to the fittings under pressure.