Why Shouldn't You Use Propane Gas in a Natural Gas Burner?

Two Differences

• The two biggest differences between natural gas and propane are the service pressure at which they are delivered to the appliance and the heat energy they produce. Propane from a tank or bottle is delivered at a much higher service pressure than natural gas from gas mains. Propane also has more than twice the heat energy per cubic foot that natural gas has. Propane produces 2,516 British thermal units per cubic foot, compared with 1,012 British thermal units for natural gas. The gas supply orifice in a natural gas burner is much larger than in a propane burner because of the lower service pressure and lower heat energy, and the natural gas burner is larger than a propane burner of similar heat output. The regulator in a natural gas appliance delivers a larger volume of gas than a propane regulator.

Bigger and Hotter

• If you put propane through an unmodified natural gas appliance, you will get a much larger and hotter flame than the natural gas appliance is designed to handle. This could have disastrous consequences. At best, you could ruin the appliance. At worst, the device could explode causing injury, death or property damage. Many types of natural gas appliances can be converted for use with propane. Water heaters, stoves, furnaces and space heaters that can be converted safely will be labeled as being convertible and may include a conversion kit in the appliance packaging. But some newer appliance models are designed for one fuel only and cannot safely be converted to another fuel. Their appliance labels will state the correct fuel and that the appliance is not convertible.

Conversion Steps

• Converting a natural gas appliance to propane involves several steps. First, you must obtain a conversion kit specifically designed for the make and model of your gas appliance. This ensures that the parts will fit correctly. Conversion involves replacing the burner’s natural gas orifice with a propane orifice that has a smaller hole. You also must replace the natural gas regulator with a propane regulator to ensure correct pressure and gas volume at the burner.

New Burner

• You may also have to replace the natural gas burner with a smaller one designed for propane. Using an improperly sized burner can result in incomplete combustion that produces deadly carbon monoxide. Lastly, you must readjust the burner’s air shutter because propane requires a different fuel-air ratio than natural gas. If you are unsure whether you are up to the conversion task, you should consult a licensed gas technician who can make a safe and reliable conversion.