Lennox 29M17 Limit Switch
When you're troubleshooting a furnace that's short-cycling or throwing a four-flash diagnostic code, the Lennox 29M17 Limit Switch is often the first component to inspect. As a critical OEM replacement part, this L215-40F limit switch is engineered to protect the heat exchanger from thermal stress. It features a fixed setpoint that opens the electrical circuit at 215°F and automatically resets once the temperature drops to 40°F, ensuring the HVAC system safety parameters are maintained without manual intervention. This high-limit control is a common fix for Lennox furnace overheating issues typically caused by restricted airflow or a failing blower motor.
Designed for precise thermal protection, the 29M17 integrates seamlessly into residential and commercial Lennox air handlers and furnaces. Its compact design allows for straightforward installation in tight plenums using standard 1/4-inch drive mounting screws. For technicians servicing furnace limit switch failures, this genuine part offers the exact resistance and response time required to match the original equipment manufacturer's specifications. Replacing a warped or "open" switch with the Lennox 29M17 restores the system to factory operation while preventing hazardous conditions like heat exchanger fatigue or rollout.
Key Benefits- Automatic Reset Logic: Features a 215°F open and 40°F close cycle, eliminating the need for manual resets during standard operation.
- Direct OEM Compatibility: Specifically designed for Lennox equipment to ensure proper fitment and electrical calibration.
- Safety Compliance: Acts as a primary furnace high-limit switch to prevent system damage and fire hazards.
- Technical Reliability: Built with high-temperature materials to withstand the rigorous duty cycles of a modern heat exchanger.
What causes a Lennox 29M17 to trip frequently?
Repeated tripping is usually a symptom of restricted airflow. Check for a clogged air filter, blocked return air vents, or buildup on the evaporator coil before assuming the switch is faulty.
How do I test if the L215-40F is actually defective?
With the power off, use a multimeter set to the OHMS scale. At room temperature, the switch should show continuity (near 0 ohms). If it reads as an open circuit when cool, it requires replacement.
Can I use a different temperature-rated switch in its place?
No. Using a switch with a higher temperature rating can lead to heat exchanger failure or a fire. Always match the "L" (Limit) and "F" (Fan/Reset) ratings specified by the manufacturer.
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: $28.47
-65%$28.47
$9.96Lennox 29M17 Limit Switch
When you're troubleshooting a furnace that's short-cycling or throwing a four-flash diagnostic code, the Lennox 29M17 Limit Switch is often the first component to inspect. As a critical OEM replacement part, this L215-40F limit switch is engineered to protect the heat exchanger from thermal stress. It features a fixed setpoint that opens the electrical circuit at 215°F and automatically resets once the temperature drops to 40°F, ensuring the HVAC system safety parameters are maintained without manual intervention. This high-limit control is a common fix for Lennox furnace overheating issues typically caused by restricted airflow or a failing blower motor.
Designed for precise thermal protection, the 29M17 integrates seamlessly into residential and commercial Lennox air handlers and furnaces. Its compact design allows for straightforward installation in tight plenums using standard 1/4-inch drive mounting screws. For technicians servicing furnace limit switch failures, this genuine part offers the exact resistance and response time required to match the original equipment manufacturer's specifications. Replacing a warped or "open" switch with the Lennox 29M17 restores the system to factory operation while preventing hazardous conditions like heat exchanger fatigue or rollout.
Key Benefits- Automatic Reset Logic: Features a 215°F open and 40°F close cycle, eliminating the need for manual resets during standard operation.
- Direct OEM Compatibility: Specifically designed for Lennox equipment to ensure proper fitment and electrical calibration.
- Safety Compliance: Acts as a primary furnace high-limit switch to prevent system damage and fire hazards.
- Technical Reliability: Built with high-temperature materials to withstand the rigorous duty cycles of a modern heat exchanger.
What causes a Lennox 29M17 to trip frequently?
Repeated tripping is usually a symptom of restricted airflow. Check for a clogged air filter, blocked return air vents, or buildup on the evaporator coil before assuming the switch is faulty.
How do I test if the L215-40F is actually defective?
With the power off, use a multimeter set to the OHMS scale. At room temperature, the switch should show continuity (near 0 ohms). If it reads as an open circuit when cool, it requires replacement.
Can I use a different temperature-rated switch in its place?
No. Using a switch with a higher temperature rating can lead to heat exchanger failure or a fire. Always match the "L" (Limit) and "F" (Fan/Reset) ratings specified by the manufacturer.
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.
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Description
When you're troubleshooting a furnace that's short-cycling or throwing a four-flash diagnostic code, the Lennox 29M17 Limit Switch is often the first component to inspect. As a critical OEM replacement part, this L215-40F limit switch is engineered to protect the heat exchanger from thermal stress. It features a fixed setpoint that opens the electrical circuit at 215°F and automatically resets once the temperature drops to 40°F, ensuring the HVAC system safety parameters are maintained without manual intervention. This high-limit control is a common fix for Lennox furnace overheating issues typically caused by restricted airflow or a failing blower motor.
Designed for precise thermal protection, the 29M17 integrates seamlessly into residential and commercial Lennox air handlers and furnaces. Its compact design allows for straightforward installation in tight plenums using standard 1/4-inch drive mounting screws. For technicians servicing furnace limit switch failures, this genuine part offers the exact resistance and response time required to match the original equipment manufacturer's specifications. Replacing a warped or "open" switch with the Lennox 29M17 restores the system to factory operation while preventing hazardous conditions like heat exchanger fatigue or rollout.
Key Benefits- Automatic Reset Logic: Features a 215°F open and 40°F close cycle, eliminating the need for manual resets during standard operation.
- Direct OEM Compatibility: Specifically designed for Lennox equipment to ensure proper fitment and electrical calibration.
- Safety Compliance: Acts as a primary furnace high-limit switch to prevent system damage and fire hazards.
- Technical Reliability: Built with high-temperature materials to withstand the rigorous duty cycles of a modern heat exchanger.
What causes a Lennox 29M17 to trip frequently?
Repeated tripping is usually a symptom of restricted airflow. Check for a clogged air filter, blocked return air vents, or buildup on the evaporator coil before assuming the switch is faulty.
How do I test if the L215-40F is actually defective?
With the power off, use a multimeter set to the OHMS scale. At room temperature, the switch should show continuity (near 0 ohms). If it reads as an open circuit when cool, it requires replacement.
Can I use a different temperature-rated switch in its place?
No. Using a switch with a higher temperature rating can lead to heat exchanger failure or a fire. Always match the "L" (Limit) and "F" (Fan/Reset) ratings specified by the manufacturer.
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.
