4.If the sensor is replaced, make sure the wires are secured like the original ones. If the new sensor wires are longer than the original, make sure the extra wire is secured so it does not create a place where moisture can collect and freeze into ice.
5. Go to the back of the unit ,and then remove the compressor cover.Remove the drain tube and duck bill assemblies.
6. If ice has formed in the drain pan under the evaporator, use the steamer to melt the ice. Point the steamer down the drain hole, and apply steam until the drain becomes clear.
7. Use a trombone cleaner available at music supply stores to clean the walls of the internal drain tube. Do not use plastic water lines. They cannot bend their way through the drain tube.