Warranty from March 3rd visit. We replaced the thermostat with a customer provided thermostat. The thermostat needed w1/e and w2 terminals jumped together at the thermostat so the heat strips would run as auxiliary heat as intended. I also replaced 1-20x20x5 media filter. I tested the system and checked the refrigerant charge. System is heating at manufacturers specifications, I do not want to adjust the charge at this time, very low temps outside today but the sub cooling is with in range for this temperature.