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OEM Carrier 40VA 120V to 24V Control Transformer for C48A303064 | National HVAC Parts
Carrier

OEM Carrier 40VA 120V to 24V Control Transformer for C48A303064 | National HVAC Parts

SKU: CARRIE-C48A303064-TRANSFORMER-HT01BD702 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier 40VA Control Transformer for Model C48A303064

This OEM control transformer (part# HT01BD702) is the factory-specified replacement for the Carrier C48A303064 packaged unit. The transformer steps down 120V line voltage to 24V AC, powering the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When this component fails, the result is total system non-response: the thermostat goes dark, no contactors pull in, and the unit will not start under any call for heating or cooling. A failed transformer is often caused by a shorted control wire or failed component that drew excess current through the secondary winding.

  • Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Factory-matched windings for OEM control circuit protection | Includes mounting hardware
  • OEM vs Generic: OEM transformers (HT01BD702) are wound to exact VA and voltage tolerances required by the Carrier control board. Undersized or off-tolerance generic units can cause nuisance tripping, control board damage, or repeated transformer burnout.
  • Install difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Always inspect low-voltage wiring for shorts before energizing the new transformer.
  • Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered for the Carrier C48A303064 packaged unit. Verify primary voltage (120V) on your unit's data plate before ordering. If your unit operates on 208/240V primary, do not install this transformer. Our parts team is available to confirm fitment before you order — same-day shipping on all in-stock OEM parts.

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 C48A303064 | National HVAC Parts?
Yes. This is the factory-specified OEM transformer for the Carrier C48A303064 | National HVAC Parts. 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 C48A303064 | National HVAC Parts?
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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