Perform a systems home care maintenance. Change filter, tested all electrical components, flushed drain line, tested thermostat, Tested both system on cool and heat, checked pressures and refrigerant. System is working properly at this time, however notice biological growth is spreading around duct work, highly recommend to add a germicidal device to the unit to stop the spreading and purify the air. Costumer decided to move forward with repairs and enhancements. Proceed to install UV germicidal light and replace thermostats provided by costumer. Thank you for choosing TE Certified,