Furnace maintenance in Braselton, Georgia. Two systems. Changed filters. Wiped down furnace cabinets. Dusted out filter cabinets. Tested combustion, found both furnaces slightly under fire, recommend recalibration to get maximum efficiency out of both furnaces. Wear and tear is present on downstairs flame safety sensor, recommend replacement of part. Recommend surge protection to protect furnaces from power surges. Replaced main level flame safety sensor. Recalibrated both furnaces. Systems are heating at this time.