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OEM Carrier 40VA 120V to 24V Transformer for C48A305052 | National HVAC Parts
Carrier

OEM Carrier 40VA 120V to 24V Transformer for C48A305052 | National HVAC Parts

SKU: CARRIE-C48A305052-TRANSFORMER-HT01BD236 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier Control Transformer 40VA 120V/24V for Model C48A305052

This is the factory-specified OEM replacement control transformer (part number HT01BD236) for the Carrier C48A305052 packaged unit. The transformer steps down line voltage from 120V to 24V AC to power the control circuit — including the thermostat, contactor coil, and all safety switches. When the transformer fails, the entire control circuit loses power: the thermostat goes blank, nothing responds to a call for heating or cooling, and the system is completely inoperative. This is often one of the first components to inspect when a unit shows zero response despite line voltage being present at the unit.

  • Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01BD236 | Factory-matched output voltage for reliable control circuit operation
  • OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances required by Carrier. Generic substitutes often run under-rated VA, causing overheating, nuisance tripping, or premature failure — especially when multiple 24V accessories share the load.
  • Install Difficulty: 2/5 — Shut off all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Verify 120V input and 24V output after installation before restoring full system power. Photograph all wiring connections before disconnecting.
  • Warranty: 1-year OEM factory warranty. Orders placed before cutoff ship same business day from our warehouse.

Compatibility: Designed specifically for the Carrier C48A305052 packaged unit. Confirm primary voltage (120V) and VA rating (40VA) on your unit's data plate before ordering. If your system runs multiple 24V accessories such as zone boards or humidifiers, verify total VA load does not exceed transformer rating. Our parts specialists are available to confirm fitment before you order — contact us with your model and serial number.

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 C48A305052 | National HVAC Parts?
Yes. This is the factory-specified OEM transformer for the Carrier C48A305052 | 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 C48A305052 | 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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