Nordyne 626279R Limit Switch

The Nordyne 626279R Limit Switch is a critical OEM replacement part designed for Intertherm, Miller, and Nordyne gas-fired furnaces. This L140-40F high limit switch functions as a fail-safe rollout control, utilizing a temperature-sensitive disc to monitor heat exchanger conditions. When the internal plenum temperature reaches the 140?F trip point, the SPST (Single Pole Single Throw) circuit opens, immediately disconnecting power to the gas valve to prevent heat exchanger damage or unsafe rollout conditions. As an automatic reset limit switch, it will re-close the circuit once the local ambient temperature drops back to 40?F, allowing the system to attempt a new ignition sequence if the thermostat continues to call for heat. Field technicians often specify this furnace safety switch when troubleshooting furnace short cycling or limit circuit error codes caused by restricted airflow or failing blower motors. This genuine HVAC replacement part ensures compliance with original factory specifications for precise thermal regulation and equipment longevity.

• Precise Thermal Protection: Engineered with a fixed 140-degree open and 40-degree close threshold for reliable safety monitoring.
• Direct OEM Compatibility: Seamlessly replaces part numbers 626279, 312579, and 6262790 in Nordyne furnace assemblies.
• Safety Integration: Prevents catastrophic equipment failure by managing rollout limit switch conditions and overheating.
• Rugged Construction: Built to withstand high-cycling environments common in residential and light commercial HVAC systems.

How do I test a Nordyne 626279R for continuity?
With the power disconnected, use a multimeter set to the Ohms or Continuity setting. At room temperature, the L140-40F switch should show a closed circuit (near zero ohms). If it reads open (OL) when cool, the internal disc has failed and the part must be replaced.

What causes a furnace limit switch to trip repeatedly?
Frequent tripping is usually a symptom of restricted airflow. Check for a clogged air filter, obstructed return vents, or a failing blower motor that is not moving enough cubic feet per minute (CFM) across the heat exchanger.

Can I use a higher temperature limit switch as a substitute?
No. You must always match the manufacturerÆs specified temperature rating. Installing a higher-rated switch can lead to dangerous overheating and potential fire hazards, as the safety will not trip when required.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.