Super tune up performed today on an Amana gas furnace with straight cool condenser installed in 2016. All electrical connections are tight with no corrosion. Gas valve, burners, igniter, inducer motor and heat exchanger are all acceptable. Evaporator coil and blower wheel are dirty and should be cleaned customer did not have a filter to change out this time. Compressor and condenser fan motor are acceptable. Refrigerant levels are in range. Outdoor unit was washed and waxed. Attic insulation is very low. Highly suggest adding insulation in the attic to help with the efficiency of the home. Suggest a level 2 duct cleaning to clean all of the duct work and the interior of the air handler including the blower wheel and evaporator coil.