Arrived on site to perform diagnostic on furnace. Homeowner is selling house and home inspection came out yesterday and found out that downstairs furnace is not operational. After inspection found that downstairs unit had no power, unit was unplugged in the attic. Plugged unit back in and powered right up. Cycled furnace for heat and it kicked on properly and started heating. System is fully operational upon departure. Charged card on file for diagnostic fee only, customer had previously called in and authorized over the phone.