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Lennox

OEM Lennox Spark Wire Harness — 18K27

SKU: LNX-18K27 Brand: Lennox
$19.95 $29.95

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Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

The genuine OEM Lennox 18K27 spark wire harness carries the high-voltage ignition signal from the control board to the spark igniter in your Lennox furnace. This dedicated harness is built with the correct insulation, connectors, and length to deliver a strong, consistent spark for reliable burner ignition. As an exact factory replacement, it plugs in cleanly without splicing or adapters.

Common failure symptoms: A worn or damaged 18K27 harness can cause weak or intermittent ignition, delayed light-off, failure to ignite, or repeated ignition lockouts. Cracked insulation, corroded terminals, or a loose connector may let the spark leak to ground, resulting in a furnace that clicks or attempts to start but never fires. Heat and vibration over time are frequent causes of harness degradation.

Why OEM matters: High-voltage spark wiring must maintain proper insulation and secure connections to fire safely and consistently. Generic wire substitutes may not withstand the heat or voltage near the burner assembly, leading to arcing or premature failure. Installing the authentic OEM 18K27 harness ensures dependable ignition and the correct, safe fit for your Lennox equipment.

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 Wiring Harness fit my Lennox OEM Lennox Spark Wire Harness — 18K27?
Yes. This is the factory-specified OEM wiring harness for the Lennox OEM Lennox Spark Wire Harness — 18K27. 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 wiring harness on my Lennox OEM Lennox Spark Wire Harness — 18K27?
Refer to your equipment service manual for model-specific steps. General approach: turn off power, photograph connections, remove old part, install new part, restore power and test. For gas components, hire a licensed technician. Email info@nationalhvacparts.com for guidance.
What symptoms mean I need a new wiring harness?
Common symptoms: unusual noises, intermittent operation, complete failure, or visible damage. Visit our diagnostic hub for symptom-based troubleshooting.
Is this wiring harness 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 wiring harness?
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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