Upon receiving the service request, I inspected the furnace and identified that the gas valve needed replacement. I carefully removed the old gas valve, ensuring all connections were safely disconnected. After installing the new gas valve, I meticulously checked all connections for proper fit and security. I then tested the furnace to confirm that the new gas valve was functioning correctly and that the furnace was operating efficiently. Once the replacement was successfully completed, I collected the payment as per the client's instructions. The furnace is now in optimal working condition, ensuring reliable heating for the client.