What should a technician check before replacing a hot surface igniter that is not lighting?

When troubleshooting a hot surface igniter that is not lighting, checking the voltage to the igniter is essential because the igniter relies on proper electrical current to reach the high temperatures necessary for ignition. If the voltage is insufficient or absent, the igniter will not heat up and will fail to ignite the gas flow, rendering it ineffective.

Monitoring the voltage allows the technician to determine if the problem lies with the igniter itself or if there are underlying electrical issues in the system, such as faulty wiring, poor connections, or issues with the control board. Ensuring that the igniter is receiving the correct voltage also assists in diagnosing whether or not replacing the igniter is the appropriate action.

While checking gas supply pressure, furnace internal temperature, and thermostat settings are all important in other contexts, they do not directly address the functionality of the hot surface igniter. Poor gas supply pressure might prevent ignition of the overall system, but if the igniter fails to light, the voltage check is crucial and serves as the first step in the troubleshooting process.