After speaking with the Montoya’s and looking into their immediate issue. We decided we also wanted to take a more thorough look at the rest of the system. The Montoya’s have an existing prv and appears to be fully functioning, holding the house at a steady 65 psi. After looking into whole house pressure examined their thermal expansion tank. Expansion tank appears to be healthy and functioning properly. We also examined the two other hose bibs. Minus a missing handle screw on the back hose bib, both apear to be in good condition and functioning properly. The Montoya’s expressed issues with hot water. After looking at duel water heater tanks, we discovered they are piggy backed. Causing the hot water load to be mainly on the first tank’s elements. After pulling panels and using my multimeter, I believe both top elements and thermostats are shot. I would highly recommend replacing all elements and thermostats, along with plumbing water heaters in tandum vs piggy backed. While installing