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Lennox

OEM Lennox Pressure Switch w/ Bracket — 51W93

SKU: LNX-51W93 Brand: Lennox
$24.95 $34.95

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Texas CMBL #19328542014
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Govt POs Accepted

The Lennox 51W93 pressure switch, supplied complete with its mounting bracket, verifies proper combustion airflow and venting in your Lennox furnace before allowing ignition. As the inducer motor spins up, it creates a negative pressure that the 51W93 senses through its port tubing. Only when adequate draft is confirmed does the switch close and permit the ignition sequence to proceed — protecting against dangerous flue blockages and improper venting.

Common failure symptoms: When this switch fails, the furnace inducer will run but the burners never light, and the control board typically flashes a pressure-switch or open-circuit fault. You may experience short-cycling, repeated lockouts, or a furnace that starts only intermittently. Cracked tubing, a stuck diaphragm, or a switch out of calibration are the usual culprits.

Why OEM matters: The 51W93 is set to the exact water-column pressure your Lennox furnace requires, and the included bracket ensures correct positioning and tubing routing. Aftermarket switches with the wrong set point can prevent ignition or bypass a genuine venting problem. The genuine OEM assembly guarantees precise calibration, proper fit, and full compatibility with 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 Pressure Switch fit my Lennox OEM Lennox Pressure Switch w/ Bracket — 51W93?
Yes. This is the factory-specified OEM pressure switch for the Lennox OEM Lennox Pressure Switch w/ Bracket — 51W93. 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 pressure switch on my Lennox OEM Lennox Pressure Switch w/ Bracket — 51W93?
Difficulty: Medium (20–30 min)
Step 1: Turn off power. Step 2: Locate pressure switch near draft inducer. Step 3: Note tubing orientation. Step 4: Disconnect tubing and wires. Step 5: Remove screw, install new switch. Step 6: Reconnect tubing and wires, restore power.
My furnace shows a pressure switch error. What do I replace?
Furnace LED showing pressure switch error = switch not detecting draft inducer airflow. Try first: clear the rubber tubing to the switch (often clogged with condensation). If problem persists, replace the pressure switch.
Is this pressure switch 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 pressure switch?
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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