Performed clean and check on gas furnace, humidifier, and ac. Conducted combustion analysis, measured temperature rise, tested all electrical components, condensate pump, inspected gas supply, flu, burner, inducer, and blower assemblies, cleaned flame sensor, changed filter and humidifier pad. Performed clean and check on AC unit. Checked refrigerant pressures, superheat and subcooling, tested all electrical components, measured temperature drop, and cleaned outdoor coil. Customer stated that the system would continuously run even when turned off at the thermostat. I found the fan option set to "on" causing the blower to run continuously. I switched it to "auto" and cycled the system in heating and then in cooling. System is operating normally at this time. Customer had $99.00 remaining on her account and I applied it to today's bill.