**Work Performed:** Diagnosed 2009 Lennox furnace with complaint of blower fan not operating. Tested ECM blower motor and confirmed motor is functional. Further testing determined that the control board is not sending signal voltage to the blower motor. **Findings:** * ECM 2.3 blower motor tested and verified operational. * Control board not providing output signal to blower motor. **Recommendations:** * Replace faulty control board. * After board replacement, test all furnace components to confirm full and proper operation.