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OEM Lennox Flame Sensor w/ Lead — 83L72
Lennox

OEM Lennox Flame Sensor w/ Lead — 83L72

SKU: LNX-83L72 Brand: Lennox
$19.95 $26.95

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Texas CMBL #19328542014
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Govt POs Accepted

The genuine OEM Lennox 83L72 flame sensor with lead confirms that a flame is present after ignition. Using flame rectification, it sends a small microamp signal to the control board verifying the burner has lit — if no flame is detected, the board closes the gas valve to prevent unburned gas from accumulating. This makes the sensor a core safety device in your Lennox furnace.

A dirty or failing flame sensor is one of the most common causes of a furnace that lights briefly then shuts off (short cycling on ignition lockout). You may also see the burner ignite for a few seconds before the gas valve closes, followed by repeated retry attempts. Oxidation and carbon buildup on the rod weaken the flame signal over time.

The pre-wired 83L72 assembly is built to the exact rod length, position, and lead length required for correct flame sensing in your Lennox unit. OEM ensures a strong, stable microamp signal and proper fit — restoring reliable ignition and safe operation.

Shipping Information

  • Orders placed before 3PM CST ship same business day
  • Standard delivery: 2-5 business days
  • Express shipping available at checkout
  • Free shipping on orders over $75
  • Tracking number emailed upon shipment

Return Policy

  • 30-day returns on unused parts in original packaging
  • Electrical parts (capacitors, contactors, control boards) are final sale once installed
  • Email info@nationalhvacparts.com to initiate a return
  • Refunds processed within 5-7 business days

Frequently Asked Questions

Does this Flame Sensor fit my Lennox OEM Lennox Flame Sensor w/ Lead — 83L72?
Yes. This is the factory-specified OEM flame sensor for the Lennox OEM Lennox Flame Sensor w/ Lead — 83L72. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.
How do I replace the flame sensor on my Lennox OEM Lennox Flame Sensor w/ Lead — 83L72?
Difficulty: Easy (10–15 min)
Step 1: Turn off power/gas. Step 2: Open furnace panel. Step 3: Locate flame sensor rod near burners. Step 4: Remove single mounting screw. Step 5: Clean rod with 400-grit sandpaper until shiny (or replace). Step 6: Reinstall and tighten. Most common furnace repair — saves $150–$300 vs technician.
My furnace lights then shuts off after a few seconds. Why?
Furnace lights then shuts off after 3–10 seconds = dirty flame sensor in 90% of cases. The sensor can’t detect flame through oxidation buildup. Fix: clean with 400-grit sandpaper (free, 15 min). If cleaning doesn’t work, replace the sensor.
Is this flame sensor compatible with Bryant or Payne too?
Many Lennox parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.
Should I use OEM or aftermarket for my Lennox flame sensor?
OEM recommended for reliability and warranty compatibility. OEM parts match exact factory specifications for proper fit, performance, and safety. While aftermarket alternatives cost less upfront, the risk of improper fit and reduced lifespan usually makes OEM the better value long-term.
How fast does National HVAC Parts ship?
Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.
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Mike Rivera
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