In a garage, a gas water heater's ignition source must be installed a minimum distance of what above the floor?

The proper installation height for the ignition source of a gas water heater in a garage is crucial for safety reasons. The correct answer indicates that the ignition source must be installed at least 18 inches above the floor. This requirement is in place to prevent flammable vapors, which can accumulate near the ground, from igniting. In garages, vehicles may leak gasoline or other flammable substances, and these vapors tend to settle close to the floor. By positioning the ignition source at a minimum of 18 inches above the ground, the risk of an explosion or fire caused by these vapors igniting is significantly reduced.

This height requirement is often part of national codes and standards that govern residential water heater installations, promoting safety in areas where flammable materials are more likely to be present. Understanding this regulation helps ensure that gas appliances operate safely and minimizes hazards in residential settings, particularly in garages where the likelihood of flammable vapor accumulation is higher.