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OEM Carrier Transformer 40VA 120V to 24V for C4850C50AK06051 | National HVAC Parts
Carrier

OEM Carrier Transformer 40VA 120V to 24V for C4850C50AK06051 | National HVAC Parts

SKU: CARRIE-C4850C50AK06051-TRANSFORMER-HT01BD236 Brand: Carrier
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Texas CMBL #19328542014
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OEM Carrier 40VA Control Transformer HT01BD236 for Model C4850C50AK06051

This OEM step-down transformer (part number HT01BD236) is the factory-specified replacement for the Carrier C4850C50AK06051 packaged unit. The transformer steps line voltage (120V) down to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When this part fails, the result is total system silence: a blank thermostat, an unresponsive control board, and a unit that won't run in any mode. It is one of the most commonly overlooked parts during a no-power diagnostic.

  • Specs: 40VA rating | 120V primary input | 24V AC secondary output | Class 2 control circuit transformer | OEM part number HT01BD236
  • OEM vs Generic: This is the factory OEM unit built to exact VA and voltage tolerances for the C4850C50AK06051. Generic transformers frequently use undersized windings that overheat under sustained thermostat demand, leading to premature failure and potential control board damage.
  • Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Label all low-voltage wires before disconnecting. Replace fuse on secondary circuit if blown.
  • Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C4850C50AK06051 packaged unit. Verify your existing transformer's VA rating and primary voltage on the unit data plate or existing component label before ordering. If your thermostat is blank and the unit breaker is confirmed on, this transformer is the first part to test with a multimeter. Order today and get same-day shipping — our fitment team is available to confirm compatibility before you buy.

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 C4850C50AK06051 | National HVAC Parts?
Yes. This is the factory-specified OEM transformer for the Carrier C4850C50AK06051 | 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 C4850C50AK06051 | 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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