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OEM Carrier 40VA 120V to 24V Control Transformer for C48A303561 | National HVAC Parts
Carrier

OEM Carrier 40VA 120V to 24V Control Transformer for C48A303561 | National HVAC Parts

SKU: CARRIE-C48A303561-TRANSFORMER-HT01BD236 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier Control Transformer 40VA for Model C48A303561

This OEM Carrier transformer (part number HT01BD236) is the factory-specified replacement for the C48A303561 packaged unit. The transformer steps down 120V line voltage to the 24V control circuit voltage required to power the thermostat, contactor coil, control board, and all low-voltage safety controls. When the transformer fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to any calls for heating or cooling, and no contactors or relays will energize.

  • Specs: 40VA rating | 120V primary / 24V secondary | Factory-matched OEM winding | Designed for Carrier packaged unit control circuit demands
  • OEM vs Generic: The OEM HT01BD236 transformer is wound to exact factory VA and voltage tolerances. Generic transformers often run undersized on VA rating, causing overheating and premature burnout — especially in systems with multiple 24V accessories such as zone boards, humidistats, or communicating thermostats.
  • Install difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter to confirm 24V output after installation. Photograph all low-voltage wiring connections before disconnecting. Always verify the secondary fuse or circuit protector after replacement.
  • Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse.

Compatibility: Fits Carrier model C48A303561 packaged unit. Verify transformer VA rating and primary/secondary voltages on your unit's wiring diagram or data plate before ordering. If you are unsure of fitment, our technical team is available to confirm the correct part for your specific unit before you order — same-day shipping 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 C48A303561 | National HVAC Parts?
Yes. This is the factory-specified OEM transformer for the Carrier C48A303561 | National HVAC Parts. 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 C48A303561 | National HVAC Parts?
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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