Furnace tune-up and safety inspection. Tested all mechanical components. Cleaned all sensors. Cleaned all pressure switch hoses and inlets. Cleaned/washed out the condensation trap and all hoses. Tested gas valve voltage and inlet/outlet pressures. Tested thermostat. Checked inducer and blower motor amperages. Replaced the furnace filter that the customer provided. Replaced the ignitor due to a heavy amount of corrosion. System is clean, heating, and operating quietly / properly at this time. Performed free inspections.