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OEM Carrier Transformer 40VA 120V to 24V for C48A403551 — Ships Today
Carrier

OEM Carrier Transformer 40VA 120V to 24V for C48A403551 — Ships Today

SKU: CARRIE-C48A403551-TRANSFORMER-HT01BD236 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier Control Transformer 40VA 120V/24V for Model C48A403551

This is the factory-specified OEM replacement control transformer (part# HT01BD236) for the Carrier C48A403551 packaged unit. The transformer steps down 120V line voltage to the 24V signal required by your thermostat, control board, contactor coil, and all low-voltage safety circuits. When this transformer fails, the entire control circuit goes dead — your thermostat goes blank, the system refuses to respond to any call for heating or cooling, and no components energize at all. It is one of the first components to check when nothing works.

  • Specs: 40VA rated | 120V primary input | 24V secondary output | OEM part number HT01BD236 | Direct factory-matched replacement for Carrier C48A403551
  • OEM vs Generic: This OEM transformer is wound and rated to Carrier's exact VA specification. Undersized or off-brand transformers can sag under load, causing erratic lockouts and nuisance tripping on connected control boards — costing far more in callbacks than the price difference.
  • Install difficulty: 2/5 — Disconnect power at the breaker and verify with a multimeter before touching any wiring. Tools needed: flathead and Phillips screwdrivers, wire nuts or terminals, multimeter. Label all low-voltage wires before disconnecting the old unit.
  • Warranty: 1-year OEM factory warranty. In-stock and ships the same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier C48A403551 packaged unit. Confirm your existing transformer's VA rating and primary/secondary voltages on the unit data plate or wiring diagram before ordering. Need fitment help? Our HVAC parts specialists verify compatibility before your order ships — call or chat today.

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 C48A403551 — Ships Today?
Yes. This is the factory-specified OEM transformer for the Carrier C48A403551 — Ships Today. 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 C48A403551 — Ships Today?
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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