Arrived at the home to preform a blue shield club maintenance on a 2015 carrier furnace. Was greeted at the door by the customer where he showed me where the furnace and thermostat were. Customer stated they had used the heater some this year and to their knowledge it has seemed to work well. While preforming the heater maintenance I checked all aspects of the heating system. Checked blower motor and induce draft motor for proper volts and amps. Checked all electrical connections, cleaned flame sensor, checked igniter for proper operation and ohms. Checked gas valve operation, also checked temperature rise, did carbon monoxide check, and also changed 3-10x20x1 filters. System is working properly at this time and no repairs needed at this time. Could not find any faults. Did mention to the customer about installing pan treatment for our spring visit.