What is the minimum height requirement for a piloted hot water heater installation?

The minimum height requirement for the installation of a piloted hot water heater is indeed 18 inches. This requirement is in place to reduce the risk of ignition of flammable vapors that may be present in garages or similar areas where water heaters might be installed. By ensuring that the water heater is elevated above this specified height, it helps to prevent the heater's flue from being compromised by low-level vapors, enhancing overall safety and compliance with building codes. The standards are established to protect against potential fire hazards, making this height critical for safe operation and installation of these appliances.