Lennox 26H65 Limit Switch

The Lennox 26H65 Limit Switch is a critical safety component designed for precise thermal regulation within residential heating systems and air handlers. This OEM Lennox replacement part is a normally closed limit control that functions on a temperature-dependent circuit: it is engineered to open when the internal cabinet or heat exchanger temperature reaches 180°F and automatically resets (closes) once the temperature drops to 150°F. As the direct replacement for 26H6501, this unit ensures backward compatibility with legacy Lennox, Armstrong, and Ducane equipment while maintaining the integrity of the furnace high limit safety chain.

For technicians in the field, the Lennox 26H65 features a standard 3-inch insert length and a two-wire connection for straightforward integration into existing control circuits. Utilizing a 150-180F auto limit switch is essential for preventing heat exchanger fatigue and potential fire hazards by interrupting power to the gas valve or heating elements during restricted airflow conditions. This high-performance HVAC limit control is built to withstand high-vibration environments, ensuring reliable automatic reset cycling and long-term system protection without the need for manual intervention after a nuisance trip.

• Precise Thermal Protection: Strictly maintains a 150°F to 180°F operating window to safeguard the heat exchanger from overheating.
• OEM Compatibility: Serves as the verified Lennox 26H6501 replacement, fitting a wide range of Lennox and Allied Air units.
• Automatic Reset Logic: Eliminates manual resets by automatically restoring the circuit once safe temperatures are reached.
• Industrial-Grade Construction: Designed specifically for the high-temperature and high-vibration environment of a furnace plenum.
• Simplified Installation: Standard 3" probe and universal wiring terminals allow for quick field swaps during service calls.

What causes the Lennox 26H65 to trip?
The switch typically opens due to restricted airflow, often caused by a dirty air filter, a failing blower motor, or blocked return ducts. If the temperature hits the 180°F threshold, the 26H65 will break the circuit to stop the heating cycle.

Is the 26H65 interchangeable with the 26H6501?
Yes, the 26H65 is the manufacturer-designated direct replacement for the 26H6501 limit switch, featuring the same electrical ratings and thermal specifications.

Can I use this switch in a non-Lennox system?
While designed as a Lennox OEM part, it is compatible with many Armstrong, Ducane, and Concord models that specify a 150-180F auto-reset limit with a 3-inch insert.

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.