What is the minimum height for a gas water heater's pilot light above the garage floor?

The minimum height for a gas water heater's pilot light above the garage floor is set at 18 inches to prevent ignition of any flammable vapors that may be present in a garage environment. This height requirement is based on safety regulations aimed at minimizing the risk of fire or explosion.

Gas water heaters produce a pilot light that serves as a constant flame for igniting the gas. If the pilot light is too low, it could trap or ignite flammable vapors, which are often heavier than air and can settle near the floor in a garage. By positioning the pilot light at least 18 inches off the ground, the risk of these vapors reaching the ignition source is significantly reduced, enhancing safety in residential settings.

The other height options either do not meet regulatory safety standards or are unnecessary elevating requirements. Therefore, the 18-inch height serves as a practical and enforced guideline for maintaining a safe environment around gas appliances.