Arrived to do a performance maintenance. Upon arrival found that the steam humidifier is not operational. Opened the unit up and started diagnosis with the air of Aprilaire tech support. Determined the humidifiers control board and the control panel need replaced. Coordinated with office to provide repair and replacement solutions. Set up for combustion analysis temperature split and static pressure tests. Verified operation of all mechanical and electronic components of the furnace. Checked blower for cleanliness and to see if there is any play in the bearings. Checked systems heat exchanger to ensure proper venting of flue gas. Furnace is operational at this time.