A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to determine that the amount of time to ignite a burner in a burner assembly has exceeded a time threshold value and that a flame was not detected by a flame sensor. The device is further configured to receive an audio signal from a microphone while operating the HVAC system, to identify an audio signature for the flame, and to determine whether the audio signature for the flame is present within the first audio signal. The device is further configured to determine a fault type based on the determination of whether the audio signature for the flame is present within the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output a recommendation identifying the component identifier.