If you are the owner or operator of this equipment please call a professional. That is not the guy who brings your propane but a commercial equipment professional. There are many possible problems that can cause the situation you describe. To answer the can you clean it question; the answer is yes. Turn off the gas where it is connected to the appliance and remove the burners from the unit. wash them in soapy water and use a suitable sized item to clear every hole in burner. Then reassemble. that is where your part ends and the pro takes over. You will be saving yourself the labor charge for the time it would take the pro to do this. make sure all parts washed are completely dry and free of water. Do not get any water on the gas valve. They hate it and will fail forever in protest from having been wet.