What is the minimum distance above the floor that a fuel-fired appliance must be installed in a garage for burner ignition safety?

The minimum distance above the floor that a fuel-fired appliance must be installed in a garage for burner ignition safety is 18 inches. This requirement is designed to mitigate the risk of ignition from flammable vapors, which can accumulate close to the ground in the event of a fuel spill or leak. By establishing a height of 18 inches, the appliance's burner is placed above the typical level where vapors are found, thus reducing the likelihood of ignition and enhancing overall safety in the garage environment. This standard is in line with safety codes and practices aimed at protecting both people and property from fire hazards associated with fuel-fired appliances.