I have a Craftsmaster 40 gallon electric water heater that is approximately 13 years old. Once it got cold outside and we started taking more hot showers, I felt like we were prematurely running out of hot water. So, I finally decided to raise the temperature on the heater yesterday afternoon.
When I woke up this morning, the hot water was barely lukewarm. I thought maybe I had adjusted the temperature in the wrong direction, but I checked the potentiometer on the tank and it was indeed at a higher setting. Neither the reset button nor the breaker at the circuit panel appears to have been tripped.
Is it possible that when I adjusted the temperature up on an already old heater, I caused a surge or something that damaged the control circuitry? If so, is it possible to repair it or should I just replace the heater at this point?