Lennox 13P93 Fan Limit Switch

Maintain precise thermal regulation and safety standards in forced-air heating systems with the Lennox 13P93 Fan Limit Switch. This genuine OEM component is the direct replacement for 11M40 (as well as 10H37 and 43F4501) and is essential for managing blower activation and high-limit protection. Engineered by Honeywell (Model L4064B2210), this HVAC combination fan and limit control features an 11.5-inch insertion length and a 3/4-inch diameter probe for accurate temperature sensing within the heat exchanger plenum.

Designed for professional installation, the Lennox 13P93 offers field-adjustable settings with a manual fan switch for continuous blower operation. It operates with an adjustable limit range of 100-250°F and a maximum element temperature of 350°F. The furnace limit switch includes multiple wiring options, including push-in receptacles for stripped wire and 1/4-inch male flag connectors. This gas furnace replacement part ensures your system prevents overheating while optimizing airflow for consistent indoor comfort. Trust this OEM Lennox furnace part to restore factory-spec performance to residential and commercial units alike.

• Broad Compatibility: Serving as the Lennox 11M40 replacement, it fits a wide range of GCS9, GS11, and residential furnace models.
• Versatile Installation: Three wiring terminal options and included mounting adapters allow for seamless integration in the field.
• Safety-First Operation: Provides reliable high-limit cutout to protect the heat exchanger from thermal stress and overheating.
• Adjustable Dial: Features adjustable fan-on and fan-off setpoints to fine-tune blower timing for maximum efficiency.
• Manual Override: Includes a manual fan switch to keep the indoor blower running during troubleshooting or for constant air filtration.

Is the 13P93 compatible with non-Lennox brands?
Yes, while it is a primary Lennox OEM part, it is a Honeywell-manufactured L4064B series control used across various brands like Allied Air, Armstrong, and Ducane.

What causes a fan limit switch to trip frequently?
Repeated tripping is usually caused by restricted airflow. Technicians should check for a clogged furnace air filter, blocked supply registers, or a failing blower motor before replacing the switch.

Can I use a shorter probe if the 11.5-inch insertion is too long?
Insertion length is critical for accurate temperature sensing. Always verify the plenum depth and ensure the probe is positioned to correctly monitor the heat exchanger's thermal discharge.

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.