A control apparatus simultaneously controls flow rates of a first fluid and a second fluid. The apparatus comprises a control valve for controlling the flow rate of the first fluid and a bleed device for bleeding the second fluid. The control valve is operatively connected to the bleed device, whereby, as the control valve is opened progressively greater amounts to increase flow of the first fluid, the bleed device is progressively closed to decrease bleeding of the second fluid, and, as the control valve is closed progressively greater amounts to decrease flow of the first fluid, the bleed device is progressively opened to increase bleeding of the second fluid. The control apparatus may be installed in a burner unit of the type having a compressor supplying pressurized air to the burner and a fuel pump supplying fuel to the burner. The control valve controls the fuel and the bleed device increases bleeding of the air as the control valve closes.