What amp contactor do I need for my Lennox system?

The correct replacement for Lennox model OEM Lennox Contactor 3-Pole 240V 40A — X3663 is this exact part. It is the factory-specified replacement with exact OEM specifications. Using a part with different specifications can cause equipment damage or void your warranty. You can verify this by checking the data plate on your Lennox equipment which lists the model number OEM Lennox Contactor 3-Pole 240V 40A — X3663.

My AC clicks but the compressor does not turn on. What is wrong?

Clicking from the outdoor unit without the compressor starting usually means a worn contactor. The contactor is the relay that sends power to the compressor. When its contacts are pitted or worn, it clicks but cannot establish a solid electrical connection. Other symptoms: visible pitting or burn marks on the contactor face, AC works intermittently, or buzzing from the contactor.

Lennox

OEM Lennox Contactor 3-Pole 240V 40A — X3663

Name: OEM Lennox Contactor 3-Pole 240V 40A — X3663
Brand: Lennox
SKU: LNX-X3663
Price: 28.95 USD
Availability: InStock

SKU: LNX-X3663 Brand: Lennox

$28.95 $38.95

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The genuine OEM Lennox X3663 is a heavy-duty 3-pole contactor rated for 240 volts and 40 amps, designed to switch line power to the compressor and outdoor fan motor in higher-capacity Lennox air conditioning and heat pump systems. The 40-amp contact rating makes it well suited to larger-tonnage units that draw more current, providing clean, reliable make-and-break switching every time the system cycles.

Common failure symptoms: burned or welded contacts that keep the condenser energized continuously, a humming or non-pulling-in coil, intermittent compressor starts, or scorched terminals and a burnt electrical smell at the outdoor unit. Contactor wear is normal over thousands of switching cycles, making this an expected maintenance replacement.

Why OEM matters: the Lennox X3663 matches the precise contact rating, coil specification, and physical footprint your equipment requires. Choosing genuine OEM guarantees correct current handling for larger loads, proper terminal fit, and maximum service life — safeguarding your compressor investment and keeping your Lennox warranty intact.

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

OEM Lennox Contactor 3-Pole 240V...

$28.95

Frequently Asked Questions

Does this Contactor fit my Lennox OEM Lennox Contactor 3-Pole 240V 40A — X3663?

Yes. This is the factory-specified OEM contactor for the Lennox OEM Lennox Contactor 3-Pole 240V 40A — X3663. 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 contactor on my Lennox OEM Lennox Contactor 3-Pole 240V 40A — X3663?

Difficulty: Medium (30–45 min)
Step 1: Turn off breaker. Step 2: Open condensing unit panel. Step 3: Photograph ALL wiring on the contactor. Step 4: Label each wire with tape. Step 5: Disconnect wires and remove old contactor. Step 6: Mount new contactor, reconnect wires matching your photo. Step 7: Restore power and test.

My AC clicks but the compressor won’t turn on. What’s wrong?

Clicking from the outdoor unit without the compressor starting = worn contactor. The contactor sends power to the compressor. When its contacts are pitted, it clicks but can’t make solid contact. Look for: visible pitting/burn marks on the contactor face, intermittent operation, or buzzing.

Is this contactor 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 contactor?

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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OEM Lennox Contactor 3-Pole 240V 40A — X3663

Shipping Information

Return Policy

Frequently Asked Questions