It acts like the thermostat is failing and giving too big an on/off window. When you take your shower, it finally turns on and then stays on long enough to heat the entire tank, but then cooling starts to take place starting at the bottom of the tank but it is not enough to restart the burner and reheat the tank.: This heater only heats enough water for about a ten minute shower with a water restrictor shower head. But if you wait 30 min. it heats enough water for a 25 min. shower. I have already replaced the thermocoupler and no change. The question is….do I replace the whole heater or anodes or what? : Respecfully,Dave
