What issue may cause burners equipped with a hot surface igniter to light for about 7 seconds and then extinguish?

Burners equipped with a hot surface igniter rely on both the igniter and a flame sensing device, typically a flame rectification sensor, to ensure proper operation. When the igniter heats up to a specified temperature, it should ignite the gas; however, if the flame sensor is faulty, it may not detect the flame. This can lead to the system shutting down the burners after a short time, typically around 7 seconds, creating the observed situation of ignition followed by extinguishment.

In this context, the role of the flame sensor is critical. It provides feedback to the control system that a flame has been established. If the sensor is malfunctioning, it will not relay the correct information, causing the burner to shut off as a safety measure. This situation illustrates the importance of the sensor in maintaining the safe and efficient operation of the heating system.

Other issues, while they may affect burner operation, are less likely to produce the specific symptoms described. For example, a clogged filter can restrict airflow but would often lead to combustion issues or continuous ignition problems, rather than a brief ignition followed by shutdown. Insufficient gas pressure can prevent proper ignition but typically wouldn’t allow for initial ignition at all. Lastly, a malfunctioning circuit board could cause various