Arrived on site to perform fall tune up on 2 2005 Lennox units. Both furnace located in attic. Upon arrival spoke to wife and she stated units have yet to be maintenance since they have lived there and would like system inspected. Advised to client I would be inspecting both unit for proper operation and efficiency. Cycled both units in heating and found unit thermostat was not operating properly due to being bad. Wife did want to replace both thermostat just to prevent future is or not operating. Upstairs was good. Filter were all replaced and supplied by husband. Found black flex ducting used and okay condition on both systems. Found blower as dirty from lack of maintenance in past years. Recommend replacing every 3 months to reduce amount of dirt from entering system. Wheel are both dirty creating high stress on motors. Recommend cleaning both blower assembly to reduce high amp drawls and run more efficiently. Both motor are starting to develop oil from over working. Down stairs is