Serviced a client's furnace by replacing the malfunctioning gas control valve. I began by shutting off the gas supply to the unit. I then meticulously uninstalled the old valve and installed a new OEM replacement part. To ensure proper and safe operation, I conducted a comprehensive leak test, measured the gas pressure, and verified the furnace was igniting and running effectively. With the repair complete, I restored gas service to the homeowner's satisfaction.