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OEM Carrier Transformer 40VA 120/24V for FC4DNF018010AAAA
Carrier

OEM Carrier Transformer 40VA 120/24V for FC4DNF018010AAAA

SKU: CARRIE-FC4DNF018010AAAA-TRANSFORMER-HT01CN241 Brand: Carrier

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Texas CMBL #19328542014
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OEM Carrier Transformer 40VA 120V/24V for Model FC4DNF018010AAAA

This OEM replacement transformer (part number HT01CN241) is the factory-specified step-down transformer for the Carrier FC4DNF018010AAAA fan coil unit. Its job is to convert 120V line voltage down to the 24V signal that powers your thermostat, control board, and all low-voltage switching components. When this transformer fails, the entire control circuit goes dark — your thermostat goes blank, the system produces no response to any call for heating or cooling, and nothing turns on. A failed transformer is often misdiagnosed as a control board failure, making correct identification critical before replacing more expensive components.

  • Specs: 40VA rating | Input: 120V AC | Output: 24V AC | OEM Part Number: HT01CN241 | Factory-matched electrical tolerances for reliable low-voltage control
  • OEM vs Generic: This is the genuine OEM Carrier transformer, wound and rated to exact factory specifications. Generic transformers often use undersized VA ratings that can overheat under full control-circuit load, leading to premature failure and potential blown fuses.
  • Install Difficulty: 2/5 — Shut off all power to the unit at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 0V before touching wiring). Photograph all wiring connections before disconnecting. The transformer mounts inside the air handler cabinet and connects to both the line-voltage side and the low-voltage control wiring harness.
  • Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Designed specifically for the Carrier FC4DNF018010AAAA fan coil unit. Always verify your existing transformer's VA rating and primary/secondary voltages on the data plate or wiring diagram before ordering. If you're unsure of fitment, our HVAC parts specialists can confirm compatibility before you purchase — same-day shipping available on all in-stock OEM parts.

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 Transformer fit my Carrier FC4DNF018010AAAA?
Yes. This is the factory-specified OEM transformer for the Carrier FC4DNF018010AAAA. 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 transformer on my Carrier FC4DNF018010AAAA?
Difficulty: Medium (30–45 min)
Step 1: Turn off breaker. Step 2: Photo wiring connections. Step 3: Disconnect wires from old transformer. Step 4: Remove mounting hardware. Step 5: Install new transformer, reconnect wires matching voltage ratings. Step 6: Verify 24V output with multimeter.
My thermostat has no power. What failed?
Thermostat with no display = failed 24V transformer (or blown control board fuse). Check the 3A/5A fuse on the control board first ($1–$5 fix). If fuse is good but no 24V output from transformer, replace transformer.
Is this transformer 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 transformer?
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
HVAC Parts Specialist — Online