What type of procedure is required prior to performing maintenance on gas appliances?

Prior to performing maintenance on gas appliances, the most critical procedure is to ensure that the gas supply is shut off and that the appliances are tagged out. This step is essential for safety, as it prevents accidental activation of the gas supply during maintenance, which could lead to dangerous situations such as gas leaks or explosions.

Tagging out the appliances serves as a clear warning to others that maintenance is being conducted, thus preventing them from inadvertently re-energizing the system. This practice is part of standard safety protocols in the industry, aiming to protect both the maintenance personnel and anyone nearby.

Visual inspections, notifications to users, and calibration of appliances are all important aspects of maintenance, but they do not address the immediate safety concerns associated with working on live gas appliances. Adequately shutting off the gas supply and tagging out the units significantly reduces risk, ensuring that the maintenance process is performed safely and effectively.