Furnace Not Heating Due to Ignition Failure

Ignition failure occurs when the furnace control board initiates a heating cycle, but the fuel source fails to ignite. Observe the burner compartment during a call for heat. If you hear the inducer motor run but see no spark or glow from the igniter, or if the burners light briefly and immediately extinguish, the ignition sequence has failed. This may be due to a faulty hot surface igniter, a malfunctioning electronic spark igniter, or a dirty flame sensor failing to detect the presence of combustion.

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