Dwyer Instruments TSW-250 Temperature Switch 318518-761 This automatic reset limit switch

This automatic reset limit switch is designed to protect the heat exchanger and blower assembly from thermal runaway by interrupting the burner circuit when temperatures reach the 200°F high-limit trip point

this is a "Coil Only" replacement item

using this genuine 17F52 assembly ensures the unit maintains its rated AFUE efficiency by facilitating proper flue gas cooling and moisture extraction

The P323423 is a complete motor and blower wheel assembly

Dwyer Instruments TSW-250 Temperature Switch 318518-761 This automatic reset limit switchThe Dwyer Instruments TSW 250 is a rugged, digital temperature switch designed for heavy duty HVACR and industrial processes. This dual stage temperature control features a weatherproof NEMA 4X enclosure, making it the standard for rooftop units and washdown environments. Operating on a universal 90 to 255 Vac power supply, the TSW 250 eliminates the need for separate models for different voltage requirements. The unit utilizes a precise PTC