What MFD capacitor do I need for my Lennox AC?

The correct replacement for Lennox model OEM Lennox Start Capacitor with Relay — 63W23 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 Start Capacitor with Relay — 63W23.

My AC hums but will not start. What part do I need?

An AC that hums but will not start is the classic symptom of a failed capacitor. The capacitor provides the electrical boost needed to start the compressor and fan motors. When it fails, you hear the hum of the motor trying to start but it cannot overcome inertia. Other symptoms include the fan spinning slowly, the AC cycling on and off rapidly, or a visibly swollen or leaking capacitor. Replacement cost: $15 to $80 for the part, DIY in 30 minutes.

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Lennox

OEM Lennox Start Capacitor with Relay — 63W23

Name: OEM Lennox Start Capacitor with Relay — 63W23
Brand: Lennox
SKU: LNX-63W23
Price: 18.95 USD
Availability: InStock

SKU: LNX-63W23 Brand: Lennox

$18.95 $24.95

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The Lennox 63W23 is a genuine OEM start capacitor with an integrated potential relay, designed to give single-phase compressors the added torque they need to start reliably. On startup the capacitor and relay work together to boost the compressor motor, and the relay then removes the start capacitor from the circuit once the motor is up to speed. It is a direct factory component for the Lennox units that call for it.

Common failure symptoms: A failing start capacitor or relay typically shows up as a compressor that hums but won't start, frequent breaker trips, hard or delayed starting, and short-cycling on the compressor overload. A capacitor that is bulged, leaking, or reading out of spec should be replaced immediately to avoid stressing the compressor windings.

Why OEM matters: Lennox specifies the exact capacitance and relay characteristics for each compressor. The genuine 63W23 is built to those values, so the relay drops the start capacitor at the correct point and the compressor starts cleanly every cycle. Generic replacements may carry the wrong rating and cause weak starts or early failure. Choose the authorized 63W23 for a proper fit and full rated performance in your Lennox 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

OEM Lennox Start Capacitor with ...

$18.95

Frequently Asked Questions

Does this Capacitor fit my Lennox OEM Lennox Start Capacitor with Relay — 63W23?

Yes. This is the factory-specified OEM capacitor for the Lennox OEM Lennox Start Capacitor with Relay — 63W23. 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 capacitor on my Lennox OEM Lennox Start Capacitor with Relay — 63W23?

Difficulty: Easy (20–30 min)
Step 1: Turn off power at breaker. Step 2: Open condensing unit panel. Step 3: Photograph the old capacitor wiring (Common/Herm/Fan). Step 4: Discharge old capacitor with insulated screwdriver. Step 5: Disconnect and remove old capacitor. Step 6: Mount new capacitor, reconnect wires to matching terminals. Step 7: Close panel, restore power, test. Tools: screwdriver, needle-nose pliers.

My AC hums but won’t start. What part do I need?

An AC that hums but won’t start is the classic symptom of a failed capacitor. The capacitor provides the electrical boost to start the compressor. When it fails, you hear humming but the motor can’t overcome inertia. Other symptoms: fan spinning slowly, AC cycling on/off rapidly, or a visibly swollen capacitor. Fix: replace capacitor ($15–$80 DIY, 30 min).

Is this capacitor 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 capacitor?

OEM strongly recommended. OEM capacitors have ±6% MFD tolerance vs aftermarket ±10%. The looser tolerance causes motor winding stress, higher temps, and shorter compressor life. Price difference is only $10–$20 — OEM is the clear value choice.

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 Start Capacitor with Relay — 63W23

Shipping Information

Return Policy

Frequently Asked Questions