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OEM Lennox Cad Cell Flame Sensor for Beckett Burner — 37H35
Lennox

OEM Lennox Cad Cell Flame Sensor for Beckett Burner — 37H35

SKU: LNX-37H35 Brand: Lennox
$49.95 $69.95

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Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

The genuine OEM Lennox 37H35 is a cadmium-sulfide (cad cell) flame sensor for Beckett oil burner assemblies used in Lennox oil-fired furnaces and boilers. This light-sensitive cell watches for the presence of flame and signals the primary control to keep the burner running — or to lock out on safety if no flame is detected. It is a critical component of your oil heat system's flame-proving and safety circuit.

Common failure symptoms: A dirty, aged, or failed cad cell causes nuisance lockouts, burner failure to stay lit, delayed ignition, or the system dropping out shortly after startup. Soot buildup on the cell face and cracked leads are frequent culprits behind intermittent flame-sensing faults.

Why OEM matters: Flame sensing is a life-safety function, and the resistance and light-response characteristics of the cad cell must match what the Beckett primary control expects. The authentic Lennox 37H35 ensures correct sensitivity, proper fit into the burner housing, and reliable safe operation — protecting both your equipment and your home.

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 Beckett Burner — 37H35?
Yes. This is the factory-specified OEM flame sensor for the Lennox Beckett Burner — 37H35. 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 Beckett Burner — 37H35?
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
HVAC Parts Specialist — Online