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OEM Carrier Transformer 40VA 120V/24V for C48A706064
Carrier

OEM Carrier Transformer 40VA 120V/24V for C48A706064

SKU: CARRIE-C48A706064-TRANSFORMER-HT01BD702 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier Transformer 40VA 120V/24V for Model C48A706064

This OEM step-down transformer (part number HT01BD702) is the factory-specified replacement for the Carrier C48A706064 packaged unit. The transformer converts 120V line voltage to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When it fails, absolutely nothing works: the thermostat goes blank, the system won't respond to any call for heating or cooling, and you may find a blown fuse on the control board from a secondary short.

  • Specs: 40VA rating | Primary: 120V | Secondary: 24V AC | OEM part number HT01BD702 | Factory-matched output tolerance for reliable control circuit performance
  • OEM vs Generic: OEM transformers are wound to exact VA and voltage specifications for the Carrier C48A706064. Generic replacements often have loose tolerances that can underpower the control board or trip thermal overloads prematurely, leading to repeat failures.
  • Install difficulty: 2/5 — Disconnect all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 24V output after install). Always photograph or label wiring connections before removal. Check and replace the 3A or 5A control fuse if blown at the same time.
  • Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed and factory-matched for the Carrier C48A706064 packaged unit. Verify your existing transformer's primary voltage, secondary voltage, and VA rating on the unit's data plate or wiring diagram before ordering. If you have questions about fitment, our HVAC parts specialists confirm compatibility before you buy — no guesswork required.

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 C48A706064?
Yes. This is the factory-specified OEM transformer for the Carrier C48A706064. 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 C48A706064?
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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