Lennox 78W57 Pressure Switch
The Lennox 78W57 Pressure Switch is a high-precision, factory-authorized OEM replacement engineered for draft proving and airflow safety monitoring in Lennox heating and cooling systems. Specifically calibrated to actuate at 0.27" WC (Water Column), this SPST pressure switch features a 1/4" barb connection for secure integration into existing 24V control circuits. Designed as a direct replacement for Lennox part number 101572-04, it is a critical safety interlock that verifies proper inducer motor operation and flue venting before allowing burner ignition. The green label identification ensures technicians can quickly verify the set point during field diagnostics. Its robust construction is built to withstand the humidity, vibration, and temperature fluctuations common in residential furnaces and air handlers, maintaining strict Lennox furnace pressure switch specifications to prevent unsafe operation or system lockouts.
Key Benefits:
- Exact OEM Calibration: Pre-set at 0.27" WC to match original factory requirements, ensuring precise airflow detection and reliable furnace startup.
- Simplified Diagnostics: Features a green label for fast identification, reducing service time when replacing failed or cycling switches.
- Enhanced Safety Interlock: Actively monitors pressure differentials to prevent combustion if the inducer fails or the flue becomes obstructed.
- Universal Compatibility: Fits various Lennox HVAC systems utilizing a 1/4 inch barb and single-pole, single-throw (SPST) configuration.
- Industrial-Grade Durability: Rated for 5 Amps at 24 VAC, providing consistent electrical contact performance over its service life.
Common Questions:
Why is my Lennox furnace showing a pressure switch open error?
This usually indicates the switch is not detecting the required 0.27" WC negative pressure. Check the 1/4" barb tubing for cracks, condensation, or debris and ensure the inducer motor is pulling a sufficient draft.
Can I use an adjustable pressure switch to replace the 78W57?
While some technicians use universal parts, using the genuine Lennox 78W57 is recommended to ensure the system operates within its engineered safety parameters without the risk of improper calibration.
What does the green label signify on this part?
Lennox uses color-coded labels to help contractors identify actuation points. The green label specifically denotes the 0.27" water column setting for this SPST assembly.
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: $234.91
-65%$234.91
$82.22Lennox 78W57 Pressure Switch
The Lennox 78W57 Pressure Switch is a high-precision, factory-authorized OEM replacement engineered for draft proving and airflow safety monitoring in Lennox heating and cooling systems. Specifically calibrated to actuate at 0.27" WC (Water Column), this SPST pressure switch features a 1/4" barb connection for secure integration into existing 24V control circuits. Designed as a direct replacement for Lennox part number 101572-04, it is a critical safety interlock that verifies proper inducer motor operation and flue venting before allowing burner ignition. The green label identification ensures technicians can quickly verify the set point during field diagnostics. Its robust construction is built to withstand the humidity, vibration, and temperature fluctuations common in residential furnaces and air handlers, maintaining strict Lennox furnace pressure switch specifications to prevent unsafe operation or system lockouts.
Key Benefits:
- Exact OEM Calibration: Pre-set at 0.27" WC to match original factory requirements, ensuring precise airflow detection and reliable furnace startup.
- Simplified Diagnostics: Features a green label for fast identification, reducing service time when replacing failed or cycling switches.
- Enhanced Safety Interlock: Actively monitors pressure differentials to prevent combustion if the inducer fails or the flue becomes obstructed.
- Universal Compatibility: Fits various Lennox HVAC systems utilizing a 1/4 inch barb and single-pole, single-throw (SPST) configuration.
- Industrial-Grade Durability: Rated for 5 Amps at 24 VAC, providing consistent electrical contact performance over its service life.
Common Questions:
Why is my Lennox furnace showing a pressure switch open error?
This usually indicates the switch is not detecting the required 0.27" WC negative pressure. Check the 1/4" barb tubing for cracks, condensation, or debris and ensure the inducer motor is pulling a sufficient draft.
Can I use an adjustable pressure switch to replace the 78W57?
While some technicians use universal parts, using the genuine Lennox 78W57 is recommended to ensure the system operates within its engineered safety parameters without the risk of improper calibration.
What does the green label signify on this part?
Lennox uses color-coded labels to help contractors identify actuation points. The green label specifically denotes the 0.27" water column setting for this SPST assembly.
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 78W57 Pressure Switch is a high-precision, factory-authorized OEM replacement engineered for draft proving and airflow safety monitoring in Lennox heating and cooling systems. Specifically calibrated to actuate at 0.27" WC (Water Column), this SPST pressure switch features a 1/4" barb connection for secure integration into existing 24V control circuits. Designed as a direct replacement for Lennox part number 101572-04, it is a critical safety interlock that verifies proper inducer motor operation and flue venting before allowing burner ignition. The green label identification ensures technicians can quickly verify the set point during field diagnostics. Its robust construction is built to withstand the humidity, vibration, and temperature fluctuations common in residential furnaces and air handlers, maintaining strict Lennox furnace pressure switch specifications to prevent unsafe operation or system lockouts.
Key Benefits:
- Exact OEM Calibration: Pre-set at 0.27" WC to match original factory requirements, ensuring precise airflow detection and reliable furnace startup.
- Simplified Diagnostics: Features a green label for fast identification, reducing service time when replacing failed or cycling switches.
- Enhanced Safety Interlock: Actively monitors pressure differentials to prevent combustion if the inducer fails or the flue becomes obstructed.
- Universal Compatibility: Fits various Lennox HVAC systems utilizing a 1/4 inch barb and single-pole, single-throw (SPST) configuration.
- Industrial-Grade Durability: Rated for 5 Amps at 24 VAC, providing consistent electrical contact performance over its service life.
Common Questions:
Why is my Lennox furnace showing a pressure switch open error?
This usually indicates the switch is not detecting the required 0.27" WC negative pressure. Check the 1/4" barb tubing for cracks, condensation, or debris and ensure the inducer motor is pulling a sufficient draft.
Can I use an adjustable pressure switch to replace the 78W57?
While some technicians use universal parts, using the genuine Lennox 78W57 is recommended to ensure the system operates within its engineered safety parameters without the risk of improper calibration.
What does the green label signify on this part?
Lennox uses color-coded labels to help contractors identify actuation points. The green label specifically denotes the 0.27" water column setting for this SPST assembly.
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.
