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OEM Carrier Transformer 40VA 120V-24V for FC4CNB042000AAAA
Carrier

OEM Carrier Transformer 40VA 120V-24V for FC4CNB042000AAAA

SKU: CARRIE-FC4CNB042000AAAA-TRANSFORMER-HT01CN241 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier Transformer 40VA 120V to 24V for Model FC4CNB042000AAAA

This is the factory OEM replacement transformer (part number HT01CN241) for the Carrier FC4CNB042000AAAA fan coil unit. The transformer steps down 120V line voltage to the 24V signal voltage that powers your thermostat, control board, and all low-voltage components. When this transformer fails, nothing in the control circuit responds — the thermostat goes blank, the system won't call for heating or cooling, and the unit appears completely dead. It is one of the most commonly overlooked causes of a no-response HVAC system.

  • Specs: Input: 120V AC | Output: 24V AC | VA Rating: 40VA | OEM Part Number: HT01CN241 | Factory-matched to Carrier FC4CNB042000AAAA wiring harness and control board
  • OEM vs Generic: This OEM transformer is wound to exact factory VA and voltage specifications. Generic replacements often deliver inconsistent output voltage under load, causing nuisance lockouts, erratic thermostat behavior, and premature control board failure.
  • Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Photograph all wiring connections before removal. Verify primary and secondary voltages with a meter before closing the unit.
  • Warranty: 1-year OEM factory warranty against defects. In stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier FC4CNB042000AAAA fan coil unit. Confirm your existing transformer's input/output voltage and VA rating on the data plate before ordering to ensure a correct match. Have questions about fitment? Our HVAC parts specialists verify compatibility before you buy — same-day shipping on all in-stock orders.

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 FC4CNB042000AAAA?
Yes. This is the factory-specified OEM transformer for the Carrier FC4CNB042000AAAA. 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 FC4CNB042000AAAA?
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