Lennox diagnostic and repair... A common problem, the board doesn't generate a spark. The gas valve opens but since there is no flame, the gas valve will again close and eventually lock out. There's nothing better than beauty days on a roof with simple problems that require simple solutions. #hvac #hvacdiagnostics #hvactroubleshooting #commericalhvac #hvacaystem #hvacbusiness #hvaclife #hvacknowledge #hvaceducation #hvacr #lennoxrtu #hvacservice | HVAC Know It All