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OEM Carrier Transformer 40VA 120V/24V for C48A902064 — HT01BD702
Carrier

OEM Carrier Transformer 40VA 120V/24V for C48A902064 — HT01BD702

SKU: CARRIE-C48A902064-TRANSFORMER-HT01BD702 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 C48A902064

This is the OEM factory-replacement control transformer (part number HT01BD702) for the Carrier C48A902064 packaged unit. The transformer steps down line voltage (120V) to the 24V signal voltage that powers your thermostat, control board, contactor coil, and all low-voltage control circuitry. When this transformer fails, the entire control circuit goes dead — the thermostat displays nothing, the system won't respond to any calls for heating or cooling, and no error codes are generated because the board itself has no power. Replacing a failed transformer is one of the first diagnostic steps any technician takes when a unit is completely unresponsive.

  • Specs: 40VA rating | Primary: 120V | Secondary: 24V | Factory-matched OEM tolerances | Terminals compatible with OEM wiring harness on C48A902064
  • OEM vs Generic: OEM transformers are wound and insulated to Carrier's exact specifications, ensuring stable 24V output under load. Generic units often suffer from voltage sag under peak demand, causing nuisance lockouts and intermittent control board faults.
  • Install difficulty: 2/5 — Disconnect power at the disconnect box and verify zero voltage with a multimeter before touching any wiring. Tools needed: flathead and Phillips screwdrivers, multimeter, needle-nose pliers. Label all wires before disconnecting. Replace the transformer with power off and confirm 24V output before closing the panel.
  • Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier C48A902064 packaged unit using OEM part number HT01BD702. Always verify your unit's data plate and existing transformer VA and voltage ratings match before ordering. Our fitment team is available to confirm compatibility before you buy — order with confidence and get your system back online fast.

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 C48A902064 — HT01BD702?
Yes. This is the factory-specified OEM transformer for the Carrier C48A902064 — HT01BD702. 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 C48A902064 — HT01BD702?
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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