Same-day shipping before 3PM CST · 35,000+ OEM Parts · Texas CMBL & SAM.gov Registered · Government POs Accepted

Menu

Home Shop All Account Cart
OEM Carrier Transformer 40VA 120V/24V for C48A803064
Carrier

OEM Carrier Transformer 40VA 120V/24V for C48A803064

SKU: CARRIE-C48A803064-TRANSFORMER-HT01BD702 Brand: Carrier

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

OEM Carrier 40VA Control Transformer HT01BD702 for Model C48A803064

This OEM control transformer (part number HT01BD702) is the factory-specified replacement for the Carrier C48A803064 packaged unit. The transformer steps down 120V line voltage to the 24V DC control circuit voltage required to power the thermostat, contactor coil, and control board. When this component fails, the entire control circuit goes dark — nothing responds, no call for heat or cool is processed, and the system appears completely dead at the thermostat.

  • Specs: 40VA rating | Primary: 120V | Secondary: 24V | Class 2 transformer | OEM part number HT01BD702 | Factory-matched output tolerance
  • OEM vs Generic: OEM transformers are wound to exact VA and voltage specifications for the Carrier C48A803064 control circuit. Generic units may deliver slightly off-voltage output, causing erratic thermostat behavior, nuisance tripping of the secondary fuse, or premature control board failure.
  • 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, wire stripper, multimeter. Label or photograph all wire connections before disconnecting the old transformer.
  • Warranty: 1-year OEM factory warranty against defects. Orders placed before cutoff ship same business day from our climate-controlled warehouse.

Compatibility: Engineered for the Carrier C48A803064 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltages on the unit's data plate before ordering. Our HVAC parts specialists are available to confirm fitment — reach out before you buy if you have any questions. In stock and ready to ship today.

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 C48A803064?
Yes. This is the factory-specified OEM transformer for the Carrier C48A803064. 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 C48A803064?
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.
Home Shop Search Account Cart
Fitment Guaranteed
MR
Mike Rivera
HVAC Parts Specialist — Online