A combination cooking appliance controls a radiant heating element provided in an oven cavity and a convection heating element provided in an air plenum with a regulating system which receives signals from multiple temperature sensors. More specifically, the appliance includes a first temperature sensor provided in an air return plenum portion for controlling the radiant heating element and a second temperature sensor arranged in a discharge air plenum portion, preferably downstream of a catalyst, for controlling the convection heating element. The heating elements are independently controlled based on the sensed temperatures to establish a desired oven cavity temperature, while accommodating for temperature fluctuations due to the incoming fresh air stream.