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

Menu

Home Shop All Account Cart
OEM Carrier Contactor 2-Pole 24V Coil for HB1AJX042000AAAA
Carrier

OEM Carrier Contactor 2-Pole 24V Coil for HB1AJX042000AAAA

SKU: CARRIE-HB1AJX042000AAAA-CONTACTOR-HN51KC024 Brand: Carrier
✓ Guaranteed to fit HB1AJX042000AAAA — or your money back. Terms

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

OEM Carrier Contactor 2-Pole 24V Coil for Model HB1AJX042000AAAA

This is the factory OEM replacement contactor (part number HN51KC024) for the Carrier HB1AJX042000AAAA condensing unit. The contactor is a high-voltage relay controlled by your thermostat's 24V signal — when the thermostat calls for cooling, the contactor closes and sends line voltage to the compressor and condenser fan motor. A failed or pitted contactor is one of the most common reasons a central air conditioner appears completely dead, hums without starting, or intermittently fails to respond to a cooling call.

  • Specs: 2-pole configuration | 24V AC coil voltage | Factory-rated amperage matched to Carrier HB1AJX042000AAAA | Replaces OEM part number HN51KC024
  • OEM vs Generic: This OEM contactor features factory-spec contact material and coil windings, ensuring proper pull-in voltage and long contact life. Generic contactors often use lower-grade contact alloys that pit faster under compressor load cycling.
  • Install difficulty: 3/5 — Always disconnect power at the disconnect box and verify zero voltage with a multimeter before starting. Tools needed: flathead and Phillips screwdrivers, 1/4" nut driver, needle-nose pliers, multimeter. Photograph all wiring connections before removing the old contactor.
  • Warranty: 1-year OEM factory warranty included. Orders placed before cutoff ship the same business day from our climate-controlled warehouse.

Compatibility: Engineered as a direct OEM replacement for the Carrier HB1AJX042000AAAA condensing unit. Cross-reference your existing contactor's pole count, coil voltage, and amperage rating against your unit's data plate before ordering. Our HVAC parts specialists are available to confirm fitment prior to purchase — reach out before you order if you have any questions.

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 $99
  • 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 Contactor fit my Carrier HB1AJX042000AAAA?
Yes. This is the factory-specified OEM contactor for the Carrier HB1AJX042000AAAA. 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 Carrier HB1AJX042000AAAA?
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 Carrier 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 Carrier 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.
Home Shop Search Account Cart
Fitment Guaranteed
MR
Mike Rivera
HVAC Parts Specialist — Online