Lennox 56W20 Auto Limit Switch 120-150°F

The Lennox 56W20 limit switch is a part of the Lennox HVAC systems. This switch has a component known as a bimetallic strip which bends when temperatures exceed safe levels and in the process causes an electrical response. This switch is at the heat source such as a furnace burner or heat exchanger. During normal operation, the switch does not activate even as the temperature rises. But if the temperature rises beyond the limit switch which has been set at 150°F, the internal element responds by cutting the electrical circuit. Such intervention works as a safeguard and turns off the heating system before the system is subjected to excessive heat that might cause a lot of harm.