Abstract: A novel dual mode, downdraft gas range provides a sealed top and sealed gas burners that can be operated effectively in a power burner mode with a downdraft exhaust and otherwise in an atmospheric mode. In the range, a separate and independently operating air/gas supply chamber for each sealed burner is supplied with a controllable flow of gas, and, in the power burner mode, with a controlled forced flow of primary combustion air from a combustion air blower and pressure-adjustable air plenum that supply all air/gas chambers, and each air/gas supply chamber is provided with a gated opening, which is operated to provide an unobstructed flow of primary combustion air from atmosphere in non-power burner operation. The mixture of air and primary combustion air flows from the air/gas supply chamber through a sealed conduit formed to be free of obstructions and abrupt changes in direction with a flow diffuser provided adjacent the gas burner.