WATER HEATER APPARATUS WITH DIFFERENTIAL CONTROL

摘要

An apparatus for a water heater is configured to control heating operation of a water heater to maintain a desired water temperature. The various embodiments comprise a sensor that provides an output indicative of the sensed temperature of water in a water heater, and a controller in communication with the sensor. The controller is operable to initiate a present call for heat where the sensed temperature is a predetermined amount below a set-point temperature. The controller is also configured to determine whether a prior call 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 one of a predetermined time period or a predetermined sensed temperature change has occurred.