A plumber attached a pressure gauge to an outside faucet to demonstrate for me that my plumbing's water pressure was around 105 psi, an indication he said that the PRV had failed. He told me the water pressure should be no more than 80 psi or I could expect more problems like the leaky faucet I had him fix. The PRV is rated 25-75 psi according to the label. He recommended that the PRV be replaced. Made sense to me.

After he replaced the PRV, however, he never showed me what the pressure was, and I have to wonder if this was just a device to get me to agree to a rather expensive (for me) repair. Is this legit or just a way to get me to agree to unnecessary work?

No. it sound legit to me. I would have thought he would have attempted to adjust the old PRV before replacing, just in case it was just not properly adjusted. Maybe he did. But at 105 lbs it probably was defective. You can purchase a pressure gauge (about $10) that connects to your hose bib and check your pressure yourself.

I agree with Harold. Sounds like the prv needed replacement, as it was way out of range at 105psi. I would also suggest the hose bib pressure gauge. You most likely have noticed a difference in pressure out of faucets after new prv was installed. I would suggest getting the gauge, and setting the pressure at roughly 60psi max.

The average house pressure is 45 PSI, ( that's why water towers are 100 feett tall) 60 PSI should bhe about tops in a home. I'm with the rest of the experts. Get yourself a hose bib pressure gage, (see image) and monitor it yourself. Good luck, Tom

I also agree with Experts above. Yes, it sound legit. New PRV is factory preadjusted to 55psi. As Tom suggested, buy a gauge and do the test yourself.

Never assume that a PRV valve will maintain the same pressure. C heck the pressure monthly with a hose bib pressure gage. Good luck, Tom

I agree Tom. Especially with a reading of 105psi before prv. With pressures this high, I've found that the press will creep up through prvs, and need periodic adjustment.