Sam J - arrived to Silver club member for fall tune up on vertical furnace in attic. Spoke with customer and he explained there were not any cold spots in the house and thermostat is operating properly. System was running and thermostat was reading 72 when I arrived. Cycled thermostat off and began servicing system. Replaced 1 (20X30) air filter in grille, customer replaced other. In the future we will need to bring 2 filters for each service. Removed coil cover to inspect heat exchanger and coil. Coil is clean and heat exchanger is free of any cracks or rust. Cycled system on from thermostat and watched for proper ignition. Then I checked amperage of inducer motor then blower motor once it cycled on. Ducts connected and insulated well, return clean of any trash or debris. Checked temperature difference at grilles, which was 50 degrees. Thermostat satisfied at 72 degrees upon completion of service. Spoke with customer and informed them of the systems status. System clea