Same-day shipping before 3PM CST · 35,000+ OEM Parts · Texas CMBL & SAM.gov Registered · Government POs Accepted

Menu

Home Shop All Account Cart
OEM Lennox Flame Sensor — 12F19
Lennox

OEM Lennox Flame Sensor — 12F19

SKU: LNX-12F19 Brand: Lennox
$19.95 $26.95

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

The genuine OEM Lennox 12F19 flame sensor is a safety component in your Lennox gas furnace that verifies the burner flame is actually present after ignition. Using the flame's electrical conductivity, the sensor signals the control board to keep the gas valve open only when a flame is confirmed, and to shut off fuel immediately if it is not, preventing dangerous unburned gas buildup.

Common failure symptoms: A dirty, corroded, or failing 12F19 sensor is a leading cause of furnaces that light briefly then shut down. You may see the burners ignite for a few seconds before going out, repeated ignition attempts, short cycling on a call for heat, or a furnace lockout with no heat at all.

Why OEM matters: The Lennox 12F19 is built with the correct rod length, mounting, and material to read a stable flame-rectification signal your control board expects. Aftermarket sensors can give weak or erratic readings that trigger nuisance shutdowns. Choosing the factory OEM sensor ensures reliable flame detection, safe operation, and full compatibility with your Lennox furnace.

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 — 12F19?
Yes. This is the factory-specified OEM flame sensor for the Lennox OEM Lennox Flame Sensor — 12F19. 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 — 12F19?
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.
Home Shop Search Account Cart
Fitment Guaranteed
MR
Mike Rivera
HVAC Parts Specialist — Online