Lennox 29M18 Limit Switch
Looking for a reliable thermal cutout for your next service call? The Lennox 29M18 Limit Switch is a high-precision HVAC replacement part engineered for critical temperature monitoring in residential furnaces and air handlers. This Lennox L155-40F control acts as a crucial safety guardian, featuring a fixed 155°F high limit set point and a 40°F reset differential. Designed with a Single-Pole Double-Throw (SPDT) configuration, this switch provides the versatility needed for various furnace limit control circuits, ensuring the system deactivates if internal plenum temperatures exceed safe operating parameters. Built with a rugged metal housing to withstand demanding environments, this genuine Lennox OEM part ensures exact HVAC system compatibility and maintains the original equipment’s performance standards. Whether you are troubleshooting a cycling furnace or performing preventative maintenance, the 29M18 limit switch offers the precise thermal regulation and long-term durability that professional contractors expect from Lennox heating components.
Key Benefits- Precision Thermal Control: Fixed 155-degree Fahrenheit high-limit trip point prevents heat exchanger damage.
- OEM Reliability: Genuine Lennox 29M18 ensures a perfect fit and matches factory electrical specifications.
- Robust SPDT Design: Versatile switching capabilities for complex furnace safety circuit integration.
- Automatic Reset: Resets at 40°F to restore system operation once safe temperatures are reached.
- Industrial-Grade Construction: Durable housing resists vibration and high-heat fatigue common in HVAC air handlers.
What causes a Lennox 29M18 limit switch to trip?
A limit switch typically opens due to restricted airflow, often caused by a dirty air filter, blocked return vents, or a failing blower motor, which leads to internal temperatures exceeding 155°F.
Is the 29M18 compatible with other HVAC brands?
While designed specifically for Lennox equipment, this L155-40F switch can often be used as a technical cross-reference for other units requiring the same temperature range and SPDT mounting footprint.
How do I test if my furnace limit switch is faulty?
A technician should check for continuity across the terminals. If the switch remains open at room temperature or fails to interrupt the circuit at 155°F, it requires immediate replacement to ensure system safety.
This item is not eligible for free shipping.
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.
Original: $9.33
-65%$9.33
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Description
Looking for a reliable thermal cutout for your next service call? The Lennox 29M18 Limit Switch is a high-precision HVAC replacement part engineered for critical temperature monitoring in residential furnaces and air handlers. This Lennox L155-40F control acts as a crucial safety guardian, featuring a fixed 155°F high limit set point and a 40°F reset differential. Designed with a Single-Pole Double-Throw (SPDT) configuration, this switch provides the versatility needed for various furnace limit control circuits, ensuring the system deactivates if internal plenum temperatures exceed safe operating parameters. Built with a rugged metal housing to withstand demanding environments, this genuine Lennox OEM part ensures exact HVAC system compatibility and maintains the original equipment’s performance standards. Whether you are troubleshooting a cycling furnace or performing preventative maintenance, the 29M18 limit switch offers the precise thermal regulation and long-term durability that professional contractors expect from Lennox heating components.
Key Benefits- Precision Thermal Control: Fixed 155-degree Fahrenheit high-limit trip point prevents heat exchanger damage.
- OEM Reliability: Genuine Lennox 29M18 ensures a perfect fit and matches factory electrical specifications.
- Robust SPDT Design: Versatile switching capabilities for complex furnace safety circuit integration.
- Automatic Reset: Resets at 40°F to restore system operation once safe temperatures are reached.
- Industrial-Grade Construction: Durable housing resists vibration and high-heat fatigue common in HVAC air handlers.
What causes a Lennox 29M18 limit switch to trip?
A limit switch typically opens due to restricted airflow, often caused by a dirty air filter, blocked return vents, or a failing blower motor, which leads to internal temperatures exceeding 155°F.
Is the 29M18 compatible with other HVAC brands?
While designed specifically for Lennox equipment, this L155-40F switch can often be used as a technical cross-reference for other units requiring the same temperature range and SPDT mounting footprint.
How do I test if my furnace limit switch is faulty?
A technician should check for continuity across the terminals. If the switch remains open at room temperature or fails to interrupt the circuit at 155°F, it requires immediate replacement to ensure system safety.
This item is not eligible for free shipping.
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.
