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OEM Carrier Transformer 40VA 120V-24V for C48A604064
Carrier

OEM Carrier Transformer 40VA 120V-24V for C48A604064

SKU: CARRIE-C48A604064-TRANSFORMER-HT01BD702 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier Transformer 40VA 120V to 24V for Model C48A604064

This is the OEM factory-specified control circuit transformer (part number HT01BD702) for the Carrier C48A604064 packaged unit. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, contactor coil, and all low-voltage control circuits. When this transformer fails, absolutely nothing in the system responds — no thermostat display, no contactor pull-in, no staging — making it one of the first components to check when the system appears completely dead despite line voltage being present.

  • Specs: 40VA rated | 120V primary / 24V secondary | OEM part number HT01BD702 | Factory-matched windings for precise voltage output under load
  • OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances for the C48A604064 control circuit. Undersized or off-tolerance generic units can sag under load, causing intermittent lockouts or nuisance tripping of the secondary fuse.
  • Install difficulty: 2/5 — Disconnect power at the disconnect box and verify zero voltage with a multimeter before starting. Tools needed: flathead and Phillips screwdrivers, wire nuts or spade connectors, multimeter. Label all low-voltage wiring before disconnecting the old transformer.
  • Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C48A604064 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering. If you have questions about fitment, our HVAC parts specialists confirm compatibility before your order ships.

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 C48A604064?
Yes. This is the factory-specified OEM transformer for the Carrier C48A604064. 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 C48A604064?
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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