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 C50A804064
Carrier

OEM Carrier Transformer 40VA 120V/24V for C50A804064

SKU: CARRIE-C50A804064-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 C50A804064

This OEM step-down transformer is the factory-specified replacement for the Carrier C50A804064 commercial packaged unit. The transformer converts 120V line voltage to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When this component fails, nothing in the control system responds: the thermostat goes blank, the unit won't call for heating or cooling, and the system appears completely dead despite line power being present.

  • Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM Part Number: HT01BD702 | Factory-matched for Carrier C50A804064 packaged units
  • OEM vs Generic: This OEM transformer is wound to exact factory VA tolerances, ensuring stable 24V output under full control-circuit load. Generic transformers often deliver inconsistent secondary voltage, causing erratic board behavior, nuisance lockouts, or premature contactor coil failure.
  • Install difficulty: 2/5 — Shut off all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Verify incoming voltage and confirm 24V output before reinstalling the control panel. Photograph all wiring before disconnecting.
  • Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C50A804064 commercial rooftop/packaged unit. Verify VA rating and primary/secondary voltage on your unit's data plate before ordering. If your control board, thermostat, or contactors are unresponsive with line power confirmed, this transformer is the most common root cause. Our fitment team is available to confirm compatibility 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 C50A804064?
Yes. This is the factory-specified OEM transformer for the Carrier C50A804064. 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 C50A804064?
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