Furnace tune-up and safety inspection. Tested all mechanical components. Cleaned all sensors. Tested gas valve voltage and inlet/outlet pressures. Tested blower motor amperage. Tested the inducer motor amperage. Cleaned out the exhaust pipe. Changed the furnace filter that the customer provided. The ignitor had corrosion, and the customer agreed to replace it with a new one, with the sub-zero weather we were having. The system is clean, heating, and operating properly at this time. Performed free plumbing inspections. The customer will renew the VIP Maintenance plan.