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OEM Carrier Transformer 40VA 120V/24V for C48A802564
Carrier

OEM Carrier Transformer 40VA 120V/24V for C48A802564

SKU: CARRIE-C48A802564-TRANSFORMER-HT01BD702 Brand: Carrier

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Texas CMBL #19328542014
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OEM Carrier Control Circuit Transformer 40VA for Model C48A802564

This is the factory-specified OEM replacement transformer (part number HT01BD702) for the Carrier C48A802564 packaged unit. The transformer steps down line voltage from 120V to the 24V required by your thermostat, control board, contactor coil, and all low-voltage control circuits. When this component fails, the entire control circuit goes dark — your thermostat displays nothing, the system won't respond to any calls for heating or cooling, and no safety or diagnostic functions operate. It is often the first component to check when a unit appears completely unresponsive.

  • Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01BD702 | Factory-matched output for Carrier low-voltage control circuits
  • OEM vs Generic: This OEM transformer is wound to exact factory VA ratings and insulation class. Generic transformers frequently under-deliver on VA capacity, causing voltage sag that triggers nuisance lockouts, control board errors, and premature contactor coil failure.
  • Install difficulty: 2/5 — Disconnect power at the breaker and verify zero voltage before working. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Photograph all wiring connections before removal. Primary wires connect to line voltage — treat with appropriate caution.
  • Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Designed as the direct OEM replacement for Carrier C48A802564 packaged units. Always confirm the VA rating and voltage specifications on your unit's data plate before ordering. Not sure if this is the right part? Our HVAC parts specialists verify fitment before you purchase — reach out before you order and ship same day.

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 C48A802564?
Yes. This is the factory-specified OEM transformer for the Carrier C48A802564. 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 C48A802564?
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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