Responded to service call for a garage Big Maxx heater displaying a 2-blink error code. Diagnosed ignition failure despite normal startup sequence and gas call. Inspected control board and high voltage lead finding no cracks or damage. Performed maintenance including pressure switch clearing and flame sensor cleaning. Verified proper gas pressure. Determined spark igniter was faulty - would spark when unplugged but failed to function when properly connected. Resolved issue by replacing igniter.