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OEM Carrier 40VA 120V to 24V Control Transformer for C4850C50AK03561 | National HVAC Parts
Carrier

OEM Carrier 40VA 120V to 24V Control Transformer for C4850C50AK03561 | National HVAC Parts

SKU: CARRIE-C4850C50AK03561-TRANSFORMER-HT01BD236 Brand: Carrier
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Texas CMBL #19328542014
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OEM Carrier Transformer 40VA 120V to 24V for Model C4850C50AK03561

This is the factory OEM replacement transformer (part number HT01BD236) for the Carrier C4850C50AK03561 packaged unit. The transformer steps down 120V line voltage to the 24V control voltage required to power your thermostat, contactor coil, control board, and all low-voltage safety circuits. When this part fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to any call for heating or cooling, and no fault codes will display because the board itself has lost power.

  • Specs: Primary voltage: 120V | Secondary voltage: 24V | VA rating: 40VA | OEM part number: HT01BD236 | Factory-matched for Carrier packaged unit applications
  • OEM vs Generic: The OEM HT01BD236 transformer meets Carrier's exact VA rating and insulation class specifications. Generic transformers with undersized VA ratings can overheat under full control-circuit load, causing nuisance trips or premature failure of downstream components like the control board.
  • Install difficulty: 2/5 — Shut off power at the disconnect and verify zero voltage with a multimeter before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Label or photograph all low-voltage wiring before disconnecting. Reconnect primary wires first, then secondary.
  • Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier C4850C50AK03561 packaged unit. Always confirm your existing transformer's primary voltage, secondary voltage, and VA rating on the unit data plate or wiring diagram before ordering. Need help verifying fitment? Our HVAC parts specialists confirm compatibility before you buy — no guesswork, no returns.

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 $99
  • 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 C4850C50AK03561 | National HVAC Parts?
Yes. This is the factory-specified OEM transformer for the Carrier C4850C50AK03561 | 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 C4850C50AK03561 | 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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