If the ignitor in a hot surface ignition furnace does not energize after the inducer draft motor is engaged, what is the technician's next step?

The correct course of action after the inducer draft motor engages but the ignitor does not energize is to check for voltage through the pressure switch. The pressure switch plays a critical role in ensuring that there is proper airflow and venting before the ignition sequence can proceed. If the pressure switch does not close due to lack of proper draft, it will prevent the ignitor from receiving power, thus not allowing it to energize.

By checking for voltage through the pressure switch, the technician can determine if the switch is functioning correctly. If there is no voltage present, this indicates an issue with the pressure switch or potentially with the venting system. Once this aspect is verified, it can guide the technician in the right direction for troubleshooting further issues with the ignition system. This step is vital because it addresses the root cause before considering replacement of components or inspecting other systems that may not yet be problematic.