Systems and methods for selecting temperature setpoints

1. A controller for operating a water heater, the controller comprising:

an input device configured to input a temperature setpoint for the water heater, the input device configured to input at least one restricted setpoint above a predetermined maximum temperature; and

a processor coupled to the input device, the processor configured to:

detect that an unlock sequence has been input using at least the input device; and

in response to the detection of the unlock sequence, permit the water heater to operate at the restricted setpoint above the predetermined maximum temperature when the restricted setpoint is selected using the input device within a predetermined length of time after the detection of the unlock sequence.

2. The controller of claim 1 , wherein to detect that an unlock sequence has been input, the processor is configured to:

detect, at a first time, a first input on the input device that selects a setpoint above the predetermined maximum temperature; and

detect, at a second time subsequent to the first time, a second input on the input device that selects a lowest selectable setpoint.

3. The controller of claim 1 , wherein to detect that an unlock sequence has been input, the processor is configured to detect that a power switch for the controller is switched to an on state at the same time that the input device is set to a lowest selectable setpoint.

4. The controller of claim 1 , wherein the input device comprises a rotary knob coupled to a potentiometer.

5. The controller of claim 1 , further comprising an indicator coupled to the processor, the indicator configured to notify a user that the unlock sequence has been detected.

6. The controller of claim 1 , wherein the unlock sequence includes inputs made using only the input device.

7. The controller of claim 1 , wherein the predetermined maximum temperature is approximately 140° F.

8. A processor for a controller of a water heater, the processor configured to:

detect that an unlock sequence has been input using at least an input device coupled to the processor and configured to input at least one restricted setpoint above a predetermined maximum temperature; and

in response to the detection of the unlock sequence, permit the water heater to operate at the restricted setpoint above the predetermined maximum temperature when the restricted setpoint is selected using the input device within a predetermined length of time after the detection of the unlock sequence.

9. The processor of claim 8 , wherein to detect that an unlock sequence has been input, the processor is configured to:

detect, at a first time, a first input on the input device that selects a setpoint above the predetermined maximum temperature; and

detect, at a second time subsequent to the first time, a second input on the input device that selects a lowest selectable setpoint.

10. The processor of claim 8 , wherein to detect that an unlock sequence has been input, the processor is configured to detect that a power switch for the controller is switched to an on state at the same time that the input device is set to a lowest selectable setpoint.

11. The processor of claim 8 , wherein the processor is further configured to activate an indicator to notify a user that the unlock sequence has been detected.

12. The processor of claim 8 , wherein the unlock sequence includes inputs made using only the input device.

13. The processor of claim 8 , wherein the predetermined maximum temperature is approximately 140° F.

14. A method for operating a water heater using a controller that includes a processor coupled to an input device configured to input at least one restricted setpoint above a predetermined maximum temperature, the method comprising:

detecting, using the processor, that an unlock sequence has been input using at least the input device; and

in response to the detection of the unlock sequence, permitting, using the processor, the water heater to operate at the restricted setpoint above the predetermined maximum temperature when the restricted setpoint is selected using the input device within a predetermined length of time after the detection of the unlock sequence.

15. The method of claim 14 , wherein detecting that an unlock sequence has been input comprises:

detecting, at a first time, a first input on the input device that selects a setpoint above the predetermined maximum temperature; and

detecting, at a second time subsequent to the first time, a second input on the input device that selects a lowest selectable setpoint.

16. The method of claim 14 , wherein detecting that an unlock sequence has been input comprises detecting that a power switch for the controller is switched to an on state at the same time that the input device is set to a lowest selectable setpoint.

17. The method of claim 14 , wherein detecting that an unlock sequence has been input comprises detecting that an unlock sequence has been input using a rotary knob coupled to a potentiometer.

18. The method of claim 14 , wherein detecting that an unlock sequence has been input comprises detecting that an unlock sequence has been input using only the input device.

19. The method of claim 14 , further comprising notifying a user that the unlock sequence has been detected.

20. The method of claim 19 , wherein notifying a user comprises activating a single light emitting diode.

21. The method of claim 20 , wherein the single light emitting diode is a multi-color light emitting diode.