after about 5-8 minutes the water is becoming cooler... I have to turn up the "hot water" to keep it hot until I finish. My electic Ruud/Rheem Everkleen water heater says it is 65 gallons and was installed in 1996 (before I bought my house). Anyone have troubleshooting ideas and/or a manual? (it looks a lot like the Fury and has both the Ruud and Rheem brandnames on it).