Found unit off. Checked elements, found okay. Filled and energized unit, found closed drain error. Checked drain and float switch, found okay. Traced wires and found loose connection on board. Started unit, found heating contactor not pulling in. Checked t-stat, hi-limit and relay board. Found relay board calling for heat, no power out to heat relay. will need relay board replaced. 4/25/17 replaced control, energized unit, checked operation, found okay at this time.