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OEM Carrier Transformer 40VA 120V–24V for FV4CNB003L00ABAA
Carrier

OEM Carrier Transformer 40VA 120V–24V for FV4CNB003L00ABAA

SKU: CARRIE-FV4CNB003L00ABAA-TRANSFORMER-HT01CN236 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier Transformer 40VA 120V–24V for Model FV4CNB003L00ABAA

This is the factory OEM replacement transformer (part number HT01CN236) for the Carrier FV4CNB003L00ABAA fan coil air handler. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, and all low-voltage switching circuits. When this component fails, the entire control circuit goes dark — your thermostat will appear dead, the system will not respond to calls for heating or cooling, and no contactors or relays will energize. It is one of the first components to check when a system shows zero control-circuit response.

  • Specs: 40VA rating | 120V primary / 24V secondary | Class 2 transformer | OEM part number HT01CN236 | Factory-matched output for Carrier control boards
  • OEM vs Generic: OEM transformers are wound and potted to exact VA tolerances required by Carrier control boards. Undersized or off-tolerance aftermarket transformers can cause nuisance trips, board damage, or chronic low-voltage faults that are difficult to diagnose.
  • Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter (to confirm 24V output after install). Label and photograph all low-voltage wiring before disconnecting. Verify primary fuse or breaker is properly rated after replacement.
  • Warranty: 1-year OEM factory warranty against defects. In-stock units ship same business day when ordered before cutoff.

Compatibility: Designed and factory-specified for the Carrier FV4CNB003L00ABAA fan coil air handler. Always verify your unit's data plate voltage ratings match before installing. If you are unsure of fitment, our parts specialists can confirm compatibility before you order — same-day shipping available on all in-stock OEM components.

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 FV4CNB003L00ABAA?
Yes. This is the factory-specified OEM transformer for the Carrier FV4CNB003L00ABAA. 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 FV4CNB003L00ABAA?
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
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