What is the first step when changing an oil filter in a burner system?

Isolating the fuel supply is crucial before changing an oil filter in a burner system. This step ensures safety by preventing any accidental fuel flow that could cause leaks, spills, or fire hazards during the filter replacement process. By shutting off the fuel supply, you minimize the risk of hazardous situations and ensure that you can work on the system without the concern of flammable materials being present.

After isolating the fuel supply, the technician can safely remove the old filter, install a new one, and then proceed with the system's restart. It is a standard best practice in maintenance procedures to always ensure that fuel systems are secure before performing any service work to maintain safety and proper operation.