Super tune up performed today on a 4 year old Trane heat pump with air handler nall electrical connections are tight with no corrosion. ECM blower motor is acceptable. Blower wheel and evaporator coil are clean. Heat strips are pulling proper amperage. Compressor and condenser fan motor are acceptable. Refrigerant levels are in range. Reversing valve and defrost control board are working as they should. Outdoor unit was washed and waxed.