We have lived in this house 14 years, and the 50 gallon electric water heater was new then. We are quite often gone 2-3 days a week, and we turn off the well pump and water heater when we are gone. Recently we have noticed the water seems much hotter about 2 hours after we turn the heater back on, like the thermostat isn't sensing the temperature. Is this a sign of scale buildup in the tank? We have fairly nice, softened water, and when we drain the heater every fall, we get very little sediment or scale. Any ideas? Thanks!