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OEM Carrier Transformer 40VA 120V/24V for FK4CNF003000AGAA
Carrier

OEM Carrier Transformer 40VA 120V/24V for FK4CNF003000AGAA

SKU: CARRIE-FK4CNF003000AGAA-TRANSFORMER-HT01CN236 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier 40VA Control Transformer for Model FK4CNF003000AGAA

This is the factory OEM replacement transformer (part number HT01CN236) for the Carrier FK4CNF003000AGAA fan coil unit. The transformer steps down 120V line voltage to 24V AC to power the low-voltage control circuit — including the thermostat, contactor coil, and control board. When this transformer fails, nothing in the system responds: the thermostat goes blank, the air handler won't energize, and no heating or cooling call is processed. A faulty transformer is often the first suspect when a system goes completely dark with no error codes.

  • Specs: 40VA rated | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01CN236 | Factory-matched to Carrier FK4CNF003000AGAA fan coil specifications
  • OEM vs Generic: This OEM transformer is wound to exact VA and voltage tolerances required by the Carrier control circuit. Undersized or off-tolerance generic transformers can cause nuisance tripping, control board brownouts, and premature contactor coil failure — costing far more than the part itself.
  • Install difficulty: 2/5 — Shut off all power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire strippers, multimeter. Verify 24V output at secondary terminals after installation before restoring full system power. Always label or photograph existing wiring before disconnecting.
  • Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Designed and factory-specified for the Carrier FK4CNF003000AGAA fan coil unit. Confirm your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering. If you're unsure of fitment, our HVAC parts specialists verify compatibility before you buy — contact us with your model and serial number.

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 FK4CNF003000AGAA?
Yes. This is the factory-specified OEM transformer for the Carrier FK4CNF003000AGAA. 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 FK4CNF003000AGAA?
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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