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OEM Carrier Transformer 40VA 120V to 24V for C4850C50AW03551 — Ships Today
Carrier

OEM Carrier Transformer 40VA 120V to 24V for C4850C50AW03551 — Ships Today

SKU: CARRIE-C4850C50AW03551-TRANSFORMER-HT01BD236 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier Transformer 40VA 120V to 24V for Model C4850C50AW03551

This is the factory OEM replacement transformer (part number HT01BD236) for the Carrier C4850C50AW03551 packaged unit. The transformer steps down line voltage from 120V to the 24V AC signal that powers every component in your control circuit — thermostat, contactor coil, control board, and zone valves. When the transformer fails, absolutely nothing responds: the thermostat goes blank, the system won't call for heating or cooling, and you may measure 0V on the secondary side with a multimeter. It is one of the most commonly overlooked root causes of a completely unresponsive HVAC system.

  • Specs: Primary voltage: 120V AC | Secondary voltage: 24V AC | VA rating: 40VA | OEM part number: HT01BD236 | Factory-matched to Carrier C4850C50AW03551 control circuit requirements
  • OEM vs Generic: This OEM transformer is wound to exact factory VA and impedance specifications, ensuring stable 24V output under full control-circuit load. Generic transformers with undersized VA ratings can sag under load, causing intermittent lockouts and nuisance board faults that are difficult to diagnose.
  • Install difficulty: 2/5 — Disconnect all power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, wire nuts or spade connectors. Label primary and secondary wiring before disconnecting the old unit. Verify 24V output on secondary terminals before reassembling the control panel.
  • Warranty: 1-year OEM factory warranty against defects. In-stock units ship same business day from our warehouse when ordered before 3PM local time.

Compatibility: Designed specifically for the Carrier C4850C50AW03551 packaged unit. Always verify your unit's control voltage and VA requirements on the data plate or wiring diagram before ordering. If you have questions about fitment, our HVAC parts specialists are available to confirm compatibility before you buy — no guesswork required.

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 C4850C50AW03551 — Ships Today?
Yes. This is the factory-specified OEM transformer for the Carrier C4850C50AW03551 — Ships Today. 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 C4850C50AW03551 — Ships Today?
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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