I’ve paid $160 for diagnostics of my water heater . Error code was 8-2 which according to table on heater means “temperature sensor fault”. Technician said I need to buy FV sensor ($100) which is error code 8-0. After replacement nothing changed. I still had error 8-2. Wasted $250 and one day and I was in the same place. After temperature sensor replacement (by someone else) everything went back to normal.