What is a requirement for all gas-fired hot water heaters?

A requirement for all gas-fired hot water heaters is that they must be installed by a licensed plumber. This is crucial for several reasons. Licensed plumbers possess the necessary training, knowledge, and expertise to ensure that the installation adheres to local building codes and safety regulations, which helps prevent common hazards such as gas leaks, improper venting, or water damage. Their expertise ensures that the heater operates efficiently and safely.

Moreover, installations done by unqualified individuals can lead to potentially dangerous situations, including equipment failure and increased risks of fire or explosions. Monitoring of the water heater, continuous operation nature, and installation by unqualified people would not satisfy safety and regulatory standards; therefore, those options do not address the fundamental requirement for expertise and compliance in the installation of gas-fired hot water heaters.