The MARS 12791 is a professional-grade 50/7

A failed starting relay often shows an open circuit or visible signs of carbon buildup on the internal contacts

and Payne furnaces and packaged units

it opens the electrical circuit to the gas valve if internal plenum temperatures exceed 150°F and automatically re-closes once the temperature drops by 40°F

and sleeve required for 1/8" O

Nordyne 626391R Limit Switch The MARS 12791 is aThe Nordyne 626391R Limit Switch is a critical high temperature safety control designed for precise thermal monitoring within Nordyne, Intertherm, and Miller gas fired furnaces. This L140F automatic reset limit switch is engineered to open the electrical circuit at a fixed temperature of 140 degrees Fahrenheit, preventing heat exchanger damage and ensuring safe appliance operation during restricted airflow or over fire conditions. As a genuine OEM