What is required for gas appliances according to the NFPA 54?

The requirement for gas appliances to be installed according to manufacturer instructions is essential for ensuring safety and functionality. Each appliance comes with specific guidelines that are designed to address its unique design, characteristics, and operational needs. Adhering to these instructions helps prevent malfunctions, potential gas leaks, and hazards that could arise from incorrect installation.

Manufacturer instructions often specify critical factors like required clearances, venting methods, and connection types, which must be observed to maintain compliance with safety standards outlined in NFPA 54. This code provides a framework for the safe installation of gas piping and appliances, emphasizing that proper adherence to the manufacturer's recommendations is crucial for minimizing risks during usage.

In contrast, the other options do not align with the best practices outlined in the NFPA 54. For example, the use of non-metallic materials is not a universal requirement, and gas appliances must meet various codes and standards regardless of their materials. Furthermore, specific installation procedures are indeed required, contradicting the notion that they do not require any procedures. Lastly, while certain installations may benefit from or require the expertise of licensed electricians, the installation of gas appliances is primarily governed by gas fitting standards rather than electrical ones.