A fuel supply system for a gas burner assembly includes a fuel supply, a forced air supply, and an injection assembly positioned proximate the gas burner assembly for providing a flow of combustion air and fuel through an inlet into a fuel chamber. A pressure controlled valve is operably coupled with the fuel supply and the forced air supply, the pressure controlled valve being configured for stopping the flow of fuel when a pressure of the flow of combustion air drops below a predetermined pressure, potentially indicating a malfunction or failure of the forced air supply.