Very straight forward repair. Tools I used for my 3/4 inch valve in my home were a 9/16 wrench (I had to use a stubby), 1 1/2 inch socket for the bell housing and some steel whool to clean the copper surface.... took about 30 min total

Thank you so much for this. My in-laws needed a new water heater last weekend, which I installed, but the blowoff valve was constantly dripping, which lead me to check the water pressure and find it was way too high, which lead me to finding their 1 1/4" NR3 pressure regulator had failed. The house was built in 2005, so sometime in the last probably 10 years, the seals inside failed. I ordered the NR3XL repair kit, which the Zurn website said was the same part for both the NR3 and NR3XL, and an hour later, their water pressure is back to 60psi and the water heater pressure relief valve is no longer dripping. Thank you!

Looks easy. Bit is it? Hum. Not sure. Mine was full of crap. Needed to remove to clean. It was hardest to find new union gaskets. Got them from Cleveland Plumbing supply 440-247-2555 PN 111632 for gaskets