Water heater apparatus with differential control

An apparatus for controlling heating operation of a water heater to maintain a desired water temperature, comprising:

• a sensor that provides a value indicative of the sensed temperature of water in a water heater;
• a controller that initiates a call for heat when a difference between a set-point temperature and the sensed temperature exceeds a temperature differential setting, the controller being configured to delay the start of heating operation for a given delay time period where the controller identifies a prior call for heat within a predetermined elapsed time period preceding the present call for heat.

An apparatus for controlling heating operation of a water heater to maintain a desired water temperature, comprising:

• a sensor that provides a value indicative of the sensed temperature of water in a water heater;
• a controller that initiates a call for heat when a difference between a set-point temperature and the sensed temperature exceeds a temperature differential setting, the controller being configured to delay the start of heating operation until the sensed temperature decreases by a predetermined amount where the controller identifies a prior call for heat within a predetermined elapsed time period preceding the present call for heat.

An apparatus for controlling heating operation of a water heater to maintain a desired water temperature, comprising:

• a sensor that provides an output indicative of the sensed temperature of water in a water heater;
• a controller in communication with the sensor, the controller being operable to initiate a present call for heat where the sensed temperature is a predetermined amount below a set-point temperature, wherein the controller is configured to determine whether more than 3 prior calls for heat occurred within a predetermined elapsed time period preceding the present call for heat, and to respond thereto by delaying the start of heating operation in the present call for heat until the first occurrence of either a predetermined time of at least 10 minutes or the sensed temperature decreases by at least 8 degrees Fahrenheit.