Lennox 57W38 Limit Switch
The Lennox 57W38 Limit Switch is a critical OEM replacement part designed for high-limit temperature monitoring in residential gas and electric furnaces. This SPST (Single Pole Single Throw) safety control features a 3-inch insertion length, making it compatible with specific Lennox, Allied, Armstrong, and Ducane heating units. Engineered for precise thermal regulation, the switch is calibrated to open the circuit at 180°F to prevent heat exchanger damage and automatically reset once the temperature drops to 150°F. This auto-reset limit switch ensures the blower continues to dissipate residual heat, maintaining system integrity during cycles.
Field technicians frequently specify the 57W38 to resolve furnace short cycling or E250 error codes associated with restricted airflow. Its robust 115V construction provides reliable performance across various Lennox HVAC models, replacing legacy part numbers R46105-006 and R46105-0064. Utilizing genuine Lennox furnace parts ensures proper limit open on rise action and preserves the original equipment's performance specifications.
Key Benefits
- OEM Compatibility: Precision-fit for Lennox and Allied Air equipment, including Armstrong and Ducane models.
- Thermal Safety: Features a fixed 180-degree F open and 150-degree F close configuration for reliable overheat protection.
- Easy Installation: The 3" insert design allows for direct replacement in existing limit control mounting brackets.
- Automatic Operation: Eliminates the need for manual intervention with its auto-reset functionality.
Common Questions
What causes a Lennox limit switch to trip repeatedly?
The most frequent causes are restricted airflow due to a clogged air filter, a failing blower motor, or blocked return air vents. If the switch continues to trip after internal temperatures have stabilized, the 57W38 may have reached its end of service life.
Can I use this switch in non-Lennox furnaces?
This HVAC limit control is specifically designed for Lennox-family brands. Always verify the L3-180F temperature rating and 3-inch insertion depth before attempting to install it in other brands to ensure safe operation.
How do I test the 57W38 with a multimeter?
With the power off, a functioning limit switch should show continuity (near zero ohms) across its terminals at room temperature. If the circuit remains open while cool, the switch requires replacement.
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: $9.85
-65%$9.85
$3.45Lennox 57W38 Limit Switch
The Lennox 57W38 Limit Switch is a critical OEM replacement part designed for high-limit temperature monitoring in residential gas and electric furnaces. This SPST (Single Pole Single Throw) safety control features a 3-inch insertion length, making it compatible with specific Lennox, Allied, Armstrong, and Ducane heating units. Engineered for precise thermal regulation, the switch is calibrated to open the circuit at 180°F to prevent heat exchanger damage and automatically reset once the temperature drops to 150°F. This auto-reset limit switch ensures the blower continues to dissipate residual heat, maintaining system integrity during cycles.
Field technicians frequently specify the 57W38 to resolve furnace short cycling or E250 error codes associated with restricted airflow. Its robust 115V construction provides reliable performance across various Lennox HVAC models, replacing legacy part numbers R46105-006 and R46105-0064. Utilizing genuine Lennox furnace parts ensures proper limit open on rise action and preserves the original equipment's performance specifications.
Key Benefits
- OEM Compatibility: Precision-fit for Lennox and Allied Air equipment, including Armstrong and Ducane models.
- Thermal Safety: Features a fixed 180-degree F open and 150-degree F close configuration for reliable overheat protection.
- Easy Installation: The 3" insert design allows for direct replacement in existing limit control mounting brackets.
- Automatic Operation: Eliminates the need for manual intervention with its auto-reset functionality.
Common Questions
What causes a Lennox limit switch to trip repeatedly?
The most frequent causes are restricted airflow due to a clogged air filter, a failing blower motor, or blocked return air vents. If the switch continues to trip after internal temperatures have stabilized, the 57W38 may have reached its end of service life.
Can I use this switch in non-Lennox furnaces?
This HVAC limit control is specifically designed for Lennox-family brands. Always verify the L3-180F temperature rating and 3-inch insertion depth before attempting to install it in other brands to ensure safe operation.
How do I test the 57W38 with a multimeter?
With the power off, a functioning limit switch should show continuity (near zero ohms) across its terminals at room temperature. If the circuit remains open while cool, the switch requires replacement.
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.
Product Information
Product Information
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Description
The Lennox 57W38 Limit Switch is a critical OEM replacement part designed for high-limit temperature monitoring in residential gas and electric furnaces. This SPST (Single Pole Single Throw) safety control features a 3-inch insertion length, making it compatible with specific Lennox, Allied, Armstrong, and Ducane heating units. Engineered for precise thermal regulation, the switch is calibrated to open the circuit at 180°F to prevent heat exchanger damage and automatically reset once the temperature drops to 150°F. This auto-reset limit switch ensures the blower continues to dissipate residual heat, maintaining system integrity during cycles.
Field technicians frequently specify the 57W38 to resolve furnace short cycling or E250 error codes associated with restricted airflow. Its robust 115V construction provides reliable performance across various Lennox HVAC models, replacing legacy part numbers R46105-006 and R46105-0064. Utilizing genuine Lennox furnace parts ensures proper limit open on rise action and preserves the original equipment's performance specifications.
Key Benefits
- OEM Compatibility: Precision-fit for Lennox and Allied Air equipment, including Armstrong and Ducane models.
- Thermal Safety: Features a fixed 180-degree F open and 150-degree F close configuration for reliable overheat protection.
- Easy Installation: The 3" insert design allows for direct replacement in existing limit control mounting brackets.
- Automatic Operation: Eliminates the need for manual intervention with its auto-reset functionality.
Common Questions
What causes a Lennox limit switch to trip repeatedly?
The most frequent causes are restricted airflow due to a clogged air filter, a failing blower motor, or blocked return air vents. If the switch continues to trip after internal temperatures have stabilized, the 57W38 may have reached its end of service life.
Can I use this switch in non-Lennox furnaces?
This HVAC limit control is specifically designed for Lennox-family brands. Always verify the L3-180F temperature rating and 3-inch insertion depth before attempting to install it in other brands to ensure safe operation.
How do I test the 57W38 with a multimeter?
With the power off, a functioning limit switch should show continuity (near zero ohms) across its terminals at room temperature. If the circuit remains open while cool, the switch requires replacement.
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.
