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Lennox

OEM Lennox Defrost Control Sensor — 28W70

SKU: LNX-28W70 Brand: Lennox
$24.95 $34.95

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Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

The genuine OEM Lennox 28W70 defrost control sensor monitors the temperature of the outdoor coil on your Lennox heat pump. It signals the defrost control board to initiate a defrost cycle when frost or ice accumulates on the coil, then ends the cycle once the coil clears — keeping your heat pump running efficiently in cold weather.

Common failure symptoms: When the 28W70 sensor fails, you may notice the outdoor unit icing over and staying frozen, the heat pump running constant or excessively long defrost cycles, reduced heating capacity, or the system defaulting to auxiliary/emergency heat and driving up energy bills. Erratic or missing defrost behavior is a hallmark of a failed defrost sensor.

Why OEM matters: Defrost timing depends on a sensor calibrated to the exact resistance curve your Lennox control board expects. Generic sensors can report inaccurate temperatures, causing premature, delayed, or missed defrost cycles that stress the compressor and waste energy. The OEM Lennox 28W70 ensures accurate readings and correct defrost operation for your specific system.

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 — 28W70?
Yes. This is the factory-specified OEM sensor for the Lennox OEM Lennox Defrost Control Sensor — 28W70. 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 — 28W70?
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