Same-day shipping before 3PM CST · 35,000+ OEM Parts · Texas CMBL & SAM.gov Registered · Government POs Accepted

Menu

Home Shop All Account Cart

IMAGE COMING SOON

Lennox

OEM Lennox Pressure Switch w/ Bracket — 24L51

SKU: LNX-24L51 Brand: Lennox
$24.95 $34.95

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

The genuine OEM Lennox 24L51 pressure switch with mounting bracket is a critical safety component in your Lennox furnace. It monitors the vacuum created by the inducer motor to confirm proper venting and airflow before the ignition sequence begins. If adequate draft isn't detected, the switch prevents the furnace from firing — protecting your home from unsafe combustion and dangerous flue-gas conditions.

Common failure symptoms: When the 24L51 fails or sticks, you may experience a furnace that ignites and immediately shuts down (short cycling), a blower that runs without heat, repeated lockouts, or fault codes on the control board indicating an open or stuck pressure switch. Cracked hoses, blocked ports, or a worn diaphragm are frequent culprits.

Why OEM matters: Lennox pressure switches are calibrated to specific trip points matched to your furnace's inducer and venting design. Using a generic aftermarket switch with the wrong pressure rating can cause nuisance faults or, worse, allow unsafe operation. This factory-spec 24L51 includes the correct bracket for a proper, direct-fit installation and reliable safety performance.

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 — 24L51?
Yes. This is the factory-specified OEM pressure switch for the Lennox OEM Lennox Pressure Switch w/ Bracket — 24L51. 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 — 24L51?
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.
Home Shop Search Account Cart
Fitment Guaranteed
MR
Mike Rivera
HVAC Parts Specialist — Online