Lennox 20W37 Auto Limit Switch 120-160°F

The Lennox 20W37 is an Automatic Limit Switch, which serves to protect your HVAC equipment from over-temperature conditions. It may be better thought of as a tiny thermostat that is built to work at high temperatures. It works as a thermostat to constantly check the temperature inside the HVAC system. If the temperature goes high between 120-160°F, the switch decides to act. It always cuts off the electrical circuit, it stops the heating element from getting any hotter. This critical safety measure protects against possible harm to the equipment and in extreme cases the entire system.