Nordyne 626422R Limit Switch

The Nordyne 626422R Limit Switch is a critical safety component designed for furnace rollout protection in gas-fired and oil-fired HVAC systems. This thermal limit switch is engineered to open the circuit at a 155F cut-out temperature, immediately interrupting the gas valve circuit if flame rollout or excessive heat is detected near the burner box. As a manual reset rollout switch, it requires a technician to physically inspect the heat exchanger and venting for blockages or cracks before the system can be restarted, preventing catastrophic equipment damage or fire hazards.

Built for compatibility with Nordyne, Miller, and Intertherm furnaces, this 155 degree rollout switch features a panel mount design and standard spade terminal connections for rapid field replacement. It serves as a direct OEM replacement part for a wide range of furnace models where reliable overheating protection is required. Integrating a genuine Nortek 626422R ensures the HVAC safety control operates within exact manufacturer tolerances, maintaining the integrity of the combustion circuit.

• Ensures flame rollout protection by monitoring temperatures near the burner assembly.
• Features a reliable manual reset button, forcing a safety inspection after any trip event.
• Precision-calibrated 155F opening temperature for accurate furnace troubleshooting and safety.
• Genuine Nordyne OEM part ensures perfect fitment and terminal alignment in Intertherm and Miller units.
• High-quality construction designed to withstand the thermal stress of modern gas furnace environments.

How do I test a Nordyne 626422R rollout switch?
Disconnect the power and use a multimeter to check for continuity across the terminals. If the switch is cool and the reset button is depressed but there is no continuity, the internal bimetal disc has failed and the part requires replacement.

What causes a 155F rollout switch to trip?
Frequent trips typically indicate a clogged heat exchanger, a failing inducer motor, or restricted exhaust venting. Technicians should also verify that the gas manifold pressure is not over-fired, which can cause flames to "roll out" of the burner box.

Can I bypass this limit switch for testing?
Never bypass a rollout limit switch during normal operation. This is a primary safety control designed to prevent fire and carbon monoxide hazards. Always identify and repair the root cause of the overheating before putting the furnace back into service.

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.