and Comfortmaker furnaces

frequent tripping usually indicates restricted airflow due to a dirty filter

System Protection: Prevents oil-related buildup in pumps and evaporative systems

forcing a manual inspection of the furnace before the system can resume operation

the Intermatic K4221C incorporates a built-in 30-to-90-second time delay feature

Robertshaw 41-403 Hot Surface Ignitor and Comfortmaker furnacesThe Robertshaw 41 403 Hot Surface Ignitor (271M) is a heavy duty silicon carbide igniter designed for consistent ignition in 120V AC heating systems. As a veteran grade furnace replacement part, this unit features high purity recrystallized silicon carbide construction (Crystar), providing the structural integrity needed for demanding cycles in boilers, rooftop units, and infrared burners. It serves as the direct Robertshaw 41 403 cross reference for