System for controlling the duration of a self-clean cycle in an oven

A method and apparatus is provided for operating a self-cleaning oven in which a gas sensor, such as for measuring concentrations of CO gas, is located remote from, yet in gas communication with, an exhaust flue of the oven. The gas sensor is located at the end of an outlet tube which extends from the exhaust flue. A sample gas flow is provided to the gas sensor through the outlet tube to isolate the sensor from the heat of the oven and a filter device is located in the outlet tube for filtering the sample gas flow. A valve may be provided at the inlet to the outlet tube. The rate of change (slope) of successive readings of gas concentrations may be used to determine when the combustion of food material is complete, in order to terminate a self-cleaning cycle. As a back up method to the gas sampling system, a count of lengths or numbers of baking cycles and broiling cycles performed since a last self-cleaning cycle can be kept, and a look up table consulted to determine a length of time required for a cleaning cycle. A display is provided to advise the user that a cleaning mode is in operation and to inform the user of the amount of time remaining in the cleaning cycle.