it monitors the burner's ionized flame to provide the necessary microamp (µA) signal to the integrated furnace control

preventing heat exchanger damage and system failure due to restricted airflow or high-temperature excursions

when installed in a 243-12 model regulator

you should integrate the 243-0019 or daisy-chain multiple 243-0018 selectors in a cascading configuration

opening the electrical circuit if internal plenum temperatures exceed safe operating limits

Reznor 112107 Pressure Switch Els PW 17895 it monitors the burner's ionizedThe Reznor 112107 Pressure Switch is a critical safety component designed for precise combustion air monitoring in high efficiency heating systems. This SPST pressure switch features a 1 4" barb connection, ensuring a reliable interface with sensing lines to detect proper blower operation. Engineered for compatibility with specific Reznor unit heaters and power vented equipment, it monitors the pressure differential across the heat exchanger,