Performing a A/C checkout on a Lennox gas furnace and A/C, with a Lennox humidifier. Changed MERV 11 box filter. Replaced #35 humidifier pad and cleaned tray, tested operation. Cleaned evaporator coil and condenser coil. Checked refrigerant charge. Tested electrical components. Tested thermostat operation. Tested furnace operation. System is cleaned up and is issue free at this time. System operating normally.