Cooling tune up performed today on a 5 year old Trane heat pump. All electrical connections are tight with no corrosion. Primary drain had a blockage and was cleared on this visit. Drain pan treatment was also installed to ensure the drain stays clear. ECM blower motor is acceptable. Biological growth is present inside of the air handler suggest adding a germicidal light to kill the existing biological growth and help clean the air. Compressor and condenser fan motor are acceptable. Outdoor unit was washed and waxed. Sending all estimates to the customer via email.