this CO AUTO limit switch provides essential over-temperature protection to prevent heat exchanger damage and system failure

Maintains factory-spec flow profiles in the pilot circuit to ensure stable regulator performance

you must use the 316 stainless steel bellows models specifically rated for ammonia service

the SPDT contacts are rated for 24V to 240VAC

By utilizing advanced HVAC cooling coil technology

McDonnell & Miller 63-M-HD Head Mechanism R-410A this CO AUTO limit switchThe McDonnell & Miller 63 M HD Head Mechanism (Part Number 143200) is a heavy duty replacement head mechanism designed for the Series 63 Low Water Cut Off. Engineered for both hot water and steam boilers, this manual reset mechanical control ensures critical safety by interrupting the electrical circuit to the burner in 15 psi steam or 50 psi water applications. It features a robust float operated design and includes the No. 2 M switch, providing