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OEM Carrier Transformer 40VA 120V-24V for C50A403561
Carrier

OEM Carrier Transformer 40VA 120V-24V for C50A403561

SKU: CARRIE-C50A403561-TRANSFORMER-HT01BD236 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 C50A403561

This OEM replacement transformer (part number HT01BD236) is the factory-specified control circuit transformer for the Carrier C50A403561 commercial rooftop unit. The transformer steps down line voltage from 120V to 24V AC to power the low-voltage control circuit — including the thermostat, contactor coils, and all safety controls. When it fails, the entire control circuit goes dead: the thermostat displays nothing, relays won't energize, and the unit refuses to start regardless of demand. A failed transformer is often misdiagnosed as a board failure, so always verify 24V output at the secondary terminals before replacing more expensive components.

  • Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01BD236 | Factory-matched output tolerance for reliable low-voltage circuit protection
  • OEM vs Generic: OEM transformers include factory-correct VA rating and winding insulation class. Undersized or generic transformers can overheat under full control-circuit load, tripping thermal cutoffs and causing intermittent no-start conditions.
  • Install Difficulty: 2/5 — Shut off all power to the unit before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or terminal connectors. Photograph all wiring connections before removal. Verify 120V at primary terminals and 24V at secondary terminals after installation to confirm correct operation.
  • Warranty: 1-year OEM factory warranty against defects. In stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C50A403561 commercial rooftop unit. Confirm primary voltage (120V) and VA rating on your unit's data plate before ordering. Not sure it fits? Our HVAC parts specialists verify fitment before you place your order — contact us anytime.

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 C50A403561?
Yes. This is the factory-specified OEM transformer for the Carrier C50A403561. 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 C50A403561?
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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