York 3400-3151 Limit Switch always verify line voltage at

always verify line voltage at the light to confirm the issue isn't a tripped high-limit or blown fuse elsewhere in the circuit

Smith ProLine series equipment

Common Questions: Which water feeder series is the McDonnell & Miller 304100 compatible with

it provides the mechanical flexibility required to translate actuator torque into reliable blade positioning

Built for high-capacity applications

York 3400-3151 Limit Switch always verify line voltage atThe York S1 3400 3151 Limit Switch is a critical safety component designed for high limit thermal protection in residential and commercial HVAC systems. This OEM replacement part is engineered to monitor furnace plenum temperatures, specifically calibrated with an open point of 175F and a close point of 125F. As an automatic reset limit switch, it eliminates the need for manual intervention once temperatures return to safe operating parameters.