Sam J - arrived to Blue club member for fall tune up on upflow furnace in closet. Spoke with customer and he explained that the system has been operating properly with no issues of cold spots in the home. Replaced filter media while testing thermostat operation -14X30X1. Cycled thermostat off and began servicing system. Removed coil cover to inspect heat exchanger and coil. Coil is clean and heat exchanger is free of any cracks or rust. Hooked up gas manometer then cycled system on from thermostat and watched for proper ignition, while also checking gas pressure. I then checked amperage of inducer motor and blower motor as system went through its sequence of operation. Ducts connected and insulated well, return clean of any trash or debris. Checked temperature difference at grilles which was 48 degrees. Assembled machine and cleaned area. Set thermostat back to customers desired set point after completing service. Spoke with customer and informed him of the status of t