New here and have gotten a lot of great info from reading the site. My issue: 3 years ago, my city installed new meters that had backflow preventers on them. within a week of that, i had some pipes burst due to expanded pressure. Consequently, I called a plumber to have pipe repaired. In addition, i had them install new hot water tank, expansion tank and PRV. Everything was fine until this weekend, when i had some water discharge from the T&P valve on the tank. I 'assumed' that maybe the valve had gone bad, so i replaced it. The very next day, water again discharged from the T&P valve. I put a water pressure gauge on an outside hose bib and it registered around 60psi, but eventually creeped up to around 80. I left the gauge on the bib and checked it later today, and the tattle tale needle had spiked to 160. (my son takes long hot showers) I checked the expansion tank with a tire gauge. 0 psi, and a thump on both ends of the tank sounded like it was full of water. So, this afternoon i replaced the expansion tank. I pre-charged it to 60 psi, and adjusted the PRV til the gauge was reading was 60 on the hose bib. Install went fine, but pressure gauge has now creeped back up to 80. And will drop to about 45 when water is being used, but eventually creeps back up to around 80-90. Has the PRV gone bad after only 3 years? Would cleaning the PRV strainer help the situation, or should i just have the PRV replaced? It'll be interesting to see if any water discharges from the T&P after tomorrow. I appreciate any info you gurus can provide..