Patent ID: 7320226

Claim:
A method of controlling a freezer having a cooling surface, and a heating device for heating and defrosting the cooling surface, a compressor for cooling the freezer, a door providing access to the freezer, a control circuit connected to the heating device, a timer, and a manual defrost button, the method comprising the acts of: detecting a start time indicating when the compressor is turned on; detecting an end time indicating when the compressor is turned off; comparing the start time and end time and calculating an operating time indicating the duration of time the compressor is being operated; initiating a defrost program if the operating time is greater than a pre-determined value; initiating the defrost program if the operating time is less than the pre-determined value and the manual defrost button is actuated; the defrost program comprising: determining the time of day; preventing operation of the heating device if the time of day is within a prohibited time interval; operating the heating device to defrost the freezer if the time of day is within a permitted time interval; and stopping operation of the heating device and ending the defrost program when the temperature within the freezer is greater than 0 degrees Celsius.