Performed heating tuneup on furnace. Humidifier is not connected and customer was not interested on an estimate for a new one. Replaced batteries on the thermostat because not had corrosion buildup. Verified furnace will kick on before beginning tuneup. Proceeded to vacuum all debri off burner compartment and air circulation compartment. Inspected all electrical components and electrical wires. Wiped down all electrical wires. Checked gas pressure. Performed combustion check on heat exchanger. System is running within manufacturers specs at this time.