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OEM Carrier Transformer 40VA 120V/24V for C50A803564
Carrier

OEM Carrier Transformer 40VA 120V/24V for C50A803564

SKU: CARRIE-C50A803564-TRANSFORMER-HT01BD702 Brand: Carrier

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Texas CMBL #19328542014
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OEM Carrier Transformer 40VA 120V/24V for Model C50A803564

This OEM replacement transformer (part number HT01BD702) is the factory-specified step-down transformer for the Carrier C50A803564 commercial rooftop unit. The transformer converts 120V line voltage to the 24V AC signal that powers your control board, thermostat, contactor coils, and all low-voltage safety circuits. When the transformer fails, the entire control circuit loses power — the thermostat goes blank, the system refuses to respond to any call for heating or cooling, and no fault codes will display. A failed transformer is often misdiagnosed as a bad control board, so always test transformer output voltage before replacing more expensive components.

  • Specs: 40VA rating | 120V primary / 24V secondary | Class 2 output | Factory-matched OEM replacement for part number HT01BD702
  • OEM vs Generic: This OEM transformer is wound to Carrier's exact VA and voltage tolerance specifications. Generic transformers with undersized VA ratings can overheat under full control-circuit load, tripping thermal protection or failing prematurely — use OEM for long-term reliability on commercial equipment.
  • Install difficulty: 2/5 — Disconnect all power before servicing. Tools needed: multimeter, flathead and Phillips screwdrivers, wire nuts or spade connectors. Verify 0V at primary terminals before handling. Photograph all wiring connections prior to removal and confirm secondary output reads 24V AC after installation.
  • Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier C50A803564 commercial rooftop unit. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering to ensure proper fitment. Have questions about compatibility? Our HVAC parts specialists confirm fitment before you buy — contact us before placing your order.

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 C50A803564?
Yes. This is the factory-specified OEM transformer for the Carrier C50A803564. 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 C50A803564?
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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