34 IGNITION PROVING FAULT - Control will try three more times before lock out #14 occurs Check for: - Gas valve defective or gas valve or turned off Manual valve shut-off. Defective Hot Surface Ignitor, Low inlet gas pressure, Flame sensor must be ungrounded. Green wire MUST be connected to furnace sheet metal Proper flame sense micro amps (.5 microamps D.C. minimum, 4.0 - 6.0 nominal in HIGH HEAT) Inadequate flame carryover or rough ignition. Oxide buildup on flame sensor (clean with fine steel wool)