I trust one of the pros will answer your question about repairing this PRV. Have you gone to a plumbing shop that handles this brand and inquired about repair parts? That would be the first thing I'd do because repairing should be cheaper than replacing. As far as replacing with another one, the Watts is a very basic installation. It is soldered solidly on one end and uses a union on the other. If you can sweat a joint, it's simple. This is the only brand I am personally familar with, but I would have to assume installation of other brands would be quite similar.