High-Temperature Calibration: The 290°F trip point provides a reliable safety threshold for high-tolerance residential and commercial water heating applications

this open frame transformer provides the stable secondary voltage output required to drive contactors

Will this work if my pilot stays lit but the main burner won't fire

Designed for seamless compatibility with Johnson Controls V-3000 series actuators with a 5/16" stroke

Always verify the appliance nameplate and use a digital manometer for final calibration

Cleveland Controls DFS-221-156 Switch High-Temperature Calibration: The 290°F tripThe Cleveland Controls DFS 221 156 is a heavy duty, fixed point air pressure sensing switch engineered for precision airflow verification in HVAC, duct heater, and combustion systems. As a direct FS BO 179 cross reference, this SPDT switch is factory calibrated to actuate on a pressure rise of 0. 05" w. c. (+ 0. 02"), making it a critical safety component for proving draft in boilers and furnaces. Its open mounted design is specifically optimized for