Furnace tune-up and safety inspection. Cleaned and serviced both furnaces. Tested all mechanical components. Replaced both furnace filters that the customer provided. Cleaned all sensors. Cleaned both drain traps. Cleaned all pressure switch hoses. Replaced spark igniter and flame sensor on the basement furnace. Replaced flame sensor on attic furnace, both due to high corrosion. Tested system. Both systems are clean, heating, and operating properly at this time. First visits to the VIP service plan. Performed a free plumbing inspection.