In certain embodiments, a valve assembly can comprise a housing, a valve body and a nozzle. The housing can define a first inlet and a second inlet. The valve body can be positioned within the housing and configured to rotate between a first position for a first fuel type and a second position for a second fuel type different from the first. A control knob is operatively coupled to the valve body and to an air shutter such that rotation of the control knob controls the state of the valve body and the position of the air shutter.