Signed customer up for gold membership plan. Performed gold membership furnace tune up. Found furnace to be on and functioning when I arrived. Performed combustion analysis on furnace, furnace passed in all fields. Found signs of water under neath furnace. Found furnace drain trap to be restricted causing water to not drain properly. Found drain line exiting furnace to floor drain to be clogged. Cleared drain trap and drain line. Recommend checking underneath furnace after a day or 2 of running furnace to make sure water is drying, if not recommend calling us back to find where water is coming from. Checked electrical components, checked amp draws of fan motor and exhaust motor, checked temp rise, checked for proper staging of furnace, checked safeties in furnace for proper operation, checked flame sensor signal, found low flame signal. Cleaned flame sensor to proper reading. Everything else checked out good. Found furnace to have ECM blower motor, recommend leaving fan set to on posit