The Carrier HH12ZB170 Limit Switch is a critical safety component designed for precise thermal monitoring in high-efficiency furnace and air handling units

verify compatibility with specific 4-wire sub-bases

Heavy-Duty Construction: Built to withstand commercial-grade cycle counts

Which Lennox models use this part

Schneider Electric (Erie) AG13AC40 Actuator Els PW 17895 The Carrier HH12ZB170 Limit SwitchFor hydronic system maintenance and multi zone control, the Schneider Electric Erie AG13AC40 Actuator is the industry standard for reliable two position (on off) control. This 24V normally closed unit features a spring return fail safe mechanism, ensuring the system resets during power loss to prevent overheating or unauthorized flow. Designed for the Erie PopTop series, the "one handed" snap on installation allows technicians to replace the actuator