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Lennox

OEM Lennox Defrost Control Sensor — 63K46

SKU: LNX-63K46 Brand: Lennox
$24.95 $34.95

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Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

The genuine OEM Lennox 63K46 defrost control sensor monitors outdoor coil temperature on your Lennox heat pump and signals the control board when a defrost cycle is needed. Accurate temperature feedback from this sensor keeps the outdoor coil clear of frost buildup, protecting heating capacity and preventing compressor strain during cold-weather operation.

Common failure symptoms: A failing defrost sensor commonly causes excessive ice accumulation on the outdoor unit, defrost cycles that run too long or not at all, reduced heating output, unexpected auxiliary heat use, and higher energy bills. You may also see the system fail to exit defrost or trip fault codes at the control board.

Why OEM matters: Lennox calibrates the resistance curve of the 63K46 to match its defrost board logic precisely. Aftermarket sensors with different tolerances can cause mistimed defrost cycles, nuisance faults, or coil damage. Choosing the factory OEM part ensures correct temperature readings, reliable defrost operation, and full compatibility with your Lennox control system. Ships same day when ordered before the cutoff.

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 Sensor fit my Lennox OEM Lennox Defrost Control Sensor — 63K46?
Yes. This is the factory-specified OEM sensor for the Lennox OEM Lennox Defrost Control Sensor — 63K46. 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 sensor on my Lennox OEM Lennox Defrost Control Sensor — 63K46?
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 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 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
HVAC Parts Specialist — Online