Lennox 57W37 Limit Switch
The Lennox 57W37 Limit Switch is a critical safety component designed for precise thermal regulation in residential and commercial furnaces. This genuine OEM Lennox replacement part features an auto-reset mechanism, ensuring the system returns to standard operation once temperatures stabilize. Engineered as a normally closed circuit, the switch is calibrated to open on temperature rise at 170°F and close on temperature drop at 140°F, effectively protecting the heat exchanger from overheating conditions. With a 3-inch sensor insert length, the 57W37 provides accurate sensing within the primary airflow. It is a direct fit for numerous Lennox, Armstrong, and Ducane models, often replacing legacy part numbers such as R46105-004 and 36T01B3. For technicians, this L170-30F limit control offers a reliable solution for resolving furnace overheating codes and intermittent blower cycles caused by fatigued bimetal discs.
Key Benefits- Precise Thermal Protection: Strictly maintains a 140-170°F operating window to prevent heat exchanger damage.
- OEM Compatibility: Specifically designed for Lennox furnace limit switch replacement, ensuring proper electrical ratings and mounting alignment.
- Automatic Reset Functionality: Eliminates the need for manual intervention after a high-temperature trip once the unit cools.
- Broad Cross-Reference: Compatible with Allied Air, Armstrong, and Concord equipment, making it a versatile addition to a service truck.
What causes a Lennox furnace limit switch to trip frequently?
Frequent tripping usually indicates restricted airflow. Check for clogged air filters, blocked return air ducts, or a failing blower motor. If airflow is sufficient, the internal spring of the 57W37 may be weakened, requiring a replacement.
Is the Lennox 57W37 compatible with older Armstrong units?
Yes, this part often replaces Armstrong 46105-004 and L170-30F controls. Verify the 3-inch insert depth and the 170-degree cutout specification before installation.
Why is my furnace blower running constantly but the air is cold?
This often occurs when the limit switch circuit is open. If the Lennox 57W37 fails in the open position, the integrated control board will keep the blower energized as a safety measure to cool the furnace.
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: $31.29
-65%$31.29
$10.95Lennox 57W37 Limit Switch
The Lennox 57W37 Limit Switch is a critical safety component designed for precise thermal regulation in residential and commercial furnaces. This genuine OEM Lennox replacement part features an auto-reset mechanism, ensuring the system returns to standard operation once temperatures stabilize. Engineered as a normally closed circuit, the switch is calibrated to open on temperature rise at 170°F and close on temperature drop at 140°F, effectively protecting the heat exchanger from overheating conditions. With a 3-inch sensor insert length, the 57W37 provides accurate sensing within the primary airflow. It is a direct fit for numerous Lennox, Armstrong, and Ducane models, often replacing legacy part numbers such as R46105-004 and 36T01B3. For technicians, this L170-30F limit control offers a reliable solution for resolving furnace overheating codes and intermittent blower cycles caused by fatigued bimetal discs.
Key Benefits- Precise Thermal Protection: Strictly maintains a 140-170°F operating window to prevent heat exchanger damage.
- OEM Compatibility: Specifically designed for Lennox furnace limit switch replacement, ensuring proper electrical ratings and mounting alignment.
- Automatic Reset Functionality: Eliminates the need for manual intervention after a high-temperature trip once the unit cools.
- Broad Cross-Reference: Compatible with Allied Air, Armstrong, and Concord equipment, making it a versatile addition to a service truck.
What causes a Lennox furnace limit switch to trip frequently?
Frequent tripping usually indicates restricted airflow. Check for clogged air filters, blocked return air ducts, or a failing blower motor. If airflow is sufficient, the internal spring of the 57W37 may be weakened, requiring a replacement.
Is the Lennox 57W37 compatible with older Armstrong units?
Yes, this part often replaces Armstrong 46105-004 and L170-30F controls. Verify the 3-inch insert depth and the 170-degree cutout specification before installation.
Why is my furnace blower running constantly but the air is cold?
This often occurs when the limit switch circuit is open. If the Lennox 57W37 fails in the open position, the integrated control board will keep the blower energized as a safety measure to cool the furnace.
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.
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Description
The Lennox 57W37 Limit Switch is a critical safety component designed for precise thermal regulation in residential and commercial furnaces. This genuine OEM Lennox replacement part features an auto-reset mechanism, ensuring the system returns to standard operation once temperatures stabilize. Engineered as a normally closed circuit, the switch is calibrated to open on temperature rise at 170°F and close on temperature drop at 140°F, effectively protecting the heat exchanger from overheating conditions. With a 3-inch sensor insert length, the 57W37 provides accurate sensing within the primary airflow. It is a direct fit for numerous Lennox, Armstrong, and Ducane models, often replacing legacy part numbers such as R46105-004 and 36T01B3. For technicians, this L170-30F limit control offers a reliable solution for resolving furnace overheating codes and intermittent blower cycles caused by fatigued bimetal discs.
Key Benefits- Precise Thermal Protection: Strictly maintains a 140-170°F operating window to prevent heat exchanger damage.
- OEM Compatibility: Specifically designed for Lennox furnace limit switch replacement, ensuring proper electrical ratings and mounting alignment.
- Automatic Reset Functionality: Eliminates the need for manual intervention after a high-temperature trip once the unit cools.
- Broad Cross-Reference: Compatible with Allied Air, Armstrong, and Concord equipment, making it a versatile addition to a service truck.
What causes a Lennox furnace limit switch to trip frequently?
Frequent tripping usually indicates restricted airflow. Check for clogged air filters, blocked return air ducts, or a failing blower motor. If airflow is sufficient, the internal spring of the 57W37 may be weakened, requiring a replacement.
Is the Lennox 57W37 compatible with older Armstrong units?
Yes, this part often replaces Armstrong 46105-004 and L170-30F controls. Verify the 3-inch insert depth and the 170-degree cutout specification before installation.
Why is my furnace blower running constantly but the air is cold?
This often occurs when the limit switch circuit is open. If the Lennox 57W37 fails in the open position, the integrated control board will keep the blower energized as a safety measure to cool the furnace.
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.
