A New Manufacturing Standard for Gas Fired Hot Water Tanks

May 14, 2004

This summer marks the beginning of a new manufacturing standard--and a new design--for natural gas and propane hot water heaters. The new Standard requires that the design of gas-fired water heaters "shall not ignite flammable vapors outside the water heater created by the spilling of...gasoline onto the floor."

This new standard comes into effect July 1, 2004, for atmospherically vented water heaters. It has already begun in the United States and so far it has been a smooth transition for consumers and contractors.

Traditionally designed gas water heaters, which draw combustion air through vents at the bottom of the appliance, have occasionally ignited flammable vapors causing fire or an explosion in extremely rare instances. Flammable vapors are the byproduct of the evaporation of flammable liquids, such as gasoline or solvents, due to accidental spills, misuse or inappropriate storage in the home. When these vapors come in contact with an ignition source, they can cause a fire or explosion. It’s worth noting that most fires of this type are caused by spills of improperly stored gasoline or the improper use of gasoline within the home.

In the first redesign of water heaters in decades, the newly designed hot water heater will be available July 1, and it has been estimated that prices will rise between 50-60% for the new models with the sealed combustion chamber. Previous models will be available until existing stocks are sold out, however they will no longer be manufactured.


Just because new standards are being put in place for gas-fired hot water tanks, it doesn’t mean that your existing hot water tank is not safe. By following these simple safety precautions, you will have years of safe hot water for you and your family.

· Do not store paint, gasoline, aerosol cans, household cleaners, or any other flammable materials or volatile compounds near your gas water heater.

· If you have a workshop area in the same room as your gas water heater, be careful when using varnishes, glues, paints, turpentine and other flammable products. Vapors from these materials can be very hazardous around gas water heaters.

· Keep the area around your water heater and furnace clear of paper, magazines, debris and lint. Do not store boxes on or around them.

· Gas water heaters and furnaces need lots of air in order to burn gas safely and efficiently. Always ensure the airflow around your gas water heater is not inhibited.

· If you notice that your pilot light is no longer lit, consult a registered heating professional before attempting to light it.

· Conduct routine inspections of your gas water heater for signs of trouble and contact a registered heating professional if you notice any of the following signs: discoloration or black soot on the lower outside surface of the water heater, a pilot light that repeatedly extinguishes itself or an unusual burning smell coming from the water heater.

In case you are wondering about your furnace, because the furnace’s combustion takes place approximately 18 inches from floor level for most forced-air natural gas furnaces, they do not pose the same hazard that natural gas hot water heaters do. Furnace manufacturers are not planning design modifications, similar to the ones currently taking place for natural gas hot water heaters in the near future.