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Lennox 69W43 LB-74940B Flame Sensor Kit Angled Probe OEM Replacement

Lennox 69W43 LB-74940B Flame Sensor Kit Angled Probe OEM Replacement

Low stock: 1 left

Regular price $87.91 USD
Regular price Sale price $87.91 USD
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Key Features & Specifications

  • Genuine White-Rodgers / Lennox OEM Replacement

  • 90° Angled High-Temperature Sensor Rod

  • CSA Certified for Safety and Reliability

  • Direct Drop-in for Lennox 69W43 & LB74940B

  • Universal 1/4" Male Spade Connector

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Specifications

Product Details and Key Specifications:

  • Part Number: 790-801A1
  • Manufacturer: White-Rodgers / Emerson (Lennox Direct Replacement)
  • Part Type: Furnace Flame Sensor
  • Rod Angle: 90° Bend
  • Connector: 1/4 inch male spade connector for wiring
  • Approvals: CSA Certified
  • Shipping Weight: 1.50 lbs

description

The Lennox 69W43 Flame Sensor Kit serves as the vital "safety brain" for your furnace's combustion system, utilizing flame rectification technology to verify a successful ignition. This specific angled-probe design is engineered to sit precisely within the burner’s flame path, sending a microamp signal to the control board to confirm it is safe to keep the gas valve open. If the sensor fails to detect heat due to oxidation or cracks in the ceramic, the system will immediately shut down to prevent unburned gas from accumulating. This kit is a primary support component for high-efficiency Lennox G24, G32, and G26 series furnaces, ensuring reliable operation through the coldest winter cycles.

Key Features

  • Precision OEM Part Number: A direct factory-authorized replacement for 69W43 (LB-74940B), ensuring the angled probe geometry and mounting bracket match your burner box perfectly.
  • Angled Probe Design: Specifically shaped to reach into the optimal "sweet spot" of the burner flame, preventing nuisance lockouts caused by poor signal strength.
  • Advanced Safety Monitoring: Provides the high-sensitivity feedback required by the furnace "brain" to maintain a continuous, safe heating cycle without short-cycling.
  • Durability-Focused Construction: Features a high-grade Kanthal metal probe and a reinforced ceramic insulator designed to withstand extreme thermal expansion and contraction.
  • Complete Replacement Solution: This kit replaces aging or pitted sensors that can no longer be cleaned, restoring the factory-spec microamp signal for consistent ignition.

Product Details

  • Brand: Lennox / Allied Air
  • Manufacturer: Lennox Industries
  • Part #: LB-74940B
  • Cat #: 69W43
  • UPC/SKU: 662551372652 / 69W43
  • Weight: 0.20 Pounds
  • Voltage: Low Voltage (Microamp signal)
  • Probe Type: Angled Single Prong
  • Ignition Type: Hot Surface Ignition (HSI) and Spark Ignition compatible

🛠️ HVAC Depot Pro Tip

Take a Picture First! Before removing the old sensor, photograph the exact orientation of the angled probe and the wire lead connection. If the new sensor is installed even slightly "canted," the flame might not fully engulf the probe, leading to an intermittent "No Flame Sensed" error code. Diagnostic Check: If your furnace starts and then dies after 3 to 5 seconds, it is almost certainly a flame sensor issue. While you can sometimes clean a sensor with a light abrasive in an emergency, once the metal becomes porous or "pitted," it must be replaced to ensure the control board receives a steady, reliable signal.

Cross-Reference

  • Superseded / Legacy: 69W4301, 18L18, 18L1801, 100523-01
  • Drawing Numbers: LB-74940B, 614278-01
  • White-Rodgers/Emerson Equivalents: 760-401 (Adapter may be required)
  • Other Identifiers: PSE-L18, 69W43-LEN

Model Compatibility

  • G24 Series (Suffixes: UH, DF)
  • G26 Series (Suffixes: UH, DF)
  • G32 Series (Suffixes: V, UH)
  • G40 Series (Suffixes: UH, DF)
  • G41 Series (Suffixes: UF)
  • G51 Series (Suffixes: MPV)

Specification

Refund policy

Refund & Return Policy

Last Updated: June 2026

At HVAC Parts & Equipment Depot, customer satisfaction is important to us. This Refund & Return Policy explains how returns, exchanges, and refunds are handled for purchases made through TopHVACParts.com.

Return Eligibility

We accept returns within 30 days of delivery.

To qualify for a return:

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  • Model numbers and serial numbers must match the original purchase records.
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  • Returns requested more than 30 days after delivery.

Restocking Fee

Approved returns may be subject to a 20% restocking fee.

The restocking fee will be deducted from the refund amount after the returned item has been inspected and approved.

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If you receive a damaged, defective, or incorrect item, please contact us within 7 days of delivery.

Email: support@tophvacparts.com
Phone: (214) 734-5222

We may request photographs and additional information to help process your claim.

If the claim is approved, we will provide a replacement, exchange, or refund at no additional cost to you.

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To request an exchange, contact us at:

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Refund Process

Once your return is received and inspected, we will notify you by email regarding approval or rejection of your refund request.

If approved:

  • Refunds will be issued to the original payment method.
  • Processing typically takes 7–14 business days after approval.
  • Your financial institution may require additional time before the refund appears in your account.

Return Shipping

Customers are responsible for return shipping costs unless the return is the result of:

  • Our shipping error,
  • A defective product,
  • A damaged product received upon delivery.

Original shipping charges are non-refundable.

We recommend using a trackable shipping service and purchasing shipping insurance for higher-value items.

Return Address

HVAC Parts & Equipment Depot
1135 E Plano Parkway, Suite 8
Plano, TX 75074
United States

Professional Installation Notice

Many HVAC products require installation by a licensed HVAC professional.

HVAC Parts & Equipment Depot is not responsible for damages resulting from improper installation, misuse, unauthorized modifications, or failure to follow manufacturer instructions.

Special Orders

Special-order products must be picked up within 30 days of purchase unless other arrangements have been approved.

Unclaimed special-order products may be returned to the manufacturer and may be subject to applicable restocking fees.

Contact Us

If you have questions regarding returns, refunds, or exchanges, please contact us:

HVAC Parts & Equipment Depot

Phone: (214) 734-5222
Email: support@tophvacparts.com

Michel & Siso are very knowledgeable and explain everything to where I could understand! Amazing experience! Thank you will always come here for any AC needs. Trustworthy and excellent customer service.

Celest G.
Verified Customer
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