The Williams Comfort Products P271100 Flame Sensor is a replacement safety component designed to detect the presence of a burner flame in compatible Williams heating equipment. It works by sensing the flame and sending a signal to the control system, allowing the heater to continue operating safely when ignition is confirmed. If the flame is not detected, the sensor helps prevent cont... https://www.partshnc.com/p271100-williams-comfort-products-flame-sensor