Furnace precision tune up; clean and tune up furnace; clean burners, test ignition components, adjust gas level, test safety circuit, check indoor motors, checked all electrical components, tested indoor air flow, checked heating temperatures, and tested overall furnace operation. Recommend new high limit switch and flame safety sensor. Also recommend a humidifier tune up, air exchanger tune up, new filters, surge protector and blower wheel cleaning. Need to schedule a return trip for repairs. Also scheduled a home advisor visit with Chris Anderson. Scheduled for Thursday October 6th at 1 pm.