While this part is used in many single-stage conversions

As a genuine Source1 repair part

Engineered specifically for integration with D-3153

This 145F manual reset limit switch is specifically engineered for L1RC model furnaces and serves as the primary safety against over-temperature conditions in the blower compartment or heat exchanger

as an ICP replacement part

Weil McLain 512-050-230 Thermo-fuse While this part is usedThe Weil McLain 512 050 230 Thermo fuse is a critical safety component designed for flame rollout protection in high efficiency gas boilers. For technicians servicing residential or light commercial systems, this thermal fuse element is the last line of defense against hazardous combustion conditions. Rated for a precise opening temperature of 228C (442F), the device is engineered to interrupt the electrical circuit to the gas valve or control module