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OEM Carrier Transformer 40VA 120V to 24V for C4850C50ZN070500 — Ships Today
Carrier

OEM Carrier Transformer 40VA 120V to 24V for C4850C50ZN070500 — Ships Today

SKU: CARRIE-C4850C50ZN070500-TRANSFORMER-HT01BD236 Brand: Carrier
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Texas CMBL #19328542014
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OEM Carrier Transformer 40VA 120V/24V for Model C4850C50ZN070500

This is the factory OEM replacement transformer (part number HT01BD236) for the Carrier C4850C50ZN070500 packaged unit. The control circuit transformer steps down line voltage (120V) to the 24V signal voltage that powers the thermostat, contactor coil, gas valve, and control board. When this transformer fails, the entire control circuit goes dark — the thermostat goes blank, the system won't respond to any call for heating or cooling, and you may measure zero voltage at the 24V secondary terminals. A shorted transformer sometimes trips or blows the low-voltage fuse as well.

  • Specs: Primary: 120V AC | Secondary: 24V AC | Rating: 40VA | OEM Part Number: HT01BD236 | Factory-matched impedance and thermal protection
  • OEM vs Generic: OEM transformers from Carrier are wound to factory-specified VA ratings and include built-in thermal cutoffs that protect downstream control boards. Generic units often run marginal VA ratings that sag under peak load, causing nuisance lockouts and premature board failures.
  • Install difficulty: 2/5 — Disconnect power at the disconnect box and confirm with a multimeter before touching any wiring. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, needle-nose pliers. Photograph all wiring connections before removal. Reconnect secondary (24V) leads first, then primary (120V).
  • Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Orders placed before cutoff ship same business day from our climate-controlled warehouse.

Compatibility: Engineered specifically for the Carrier C4850C50ZN070500 packaged unit. Verify your unit's data plate shows 120V primary input and confirm OEM part number HT01BD236 before ordering. If your transformer shows signs of burn marks or a blown low-voltage fuse, inspect the downstream wiring for shorts before installing the new unit to prevent repeat failure. Our parts specialists are available to verify fitment — order with confidence and get back up and running today.

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 C4850C50ZN070500 — Ships Today?
Yes. This is the factory-specified OEM transformer for the Carrier C4850C50ZN070500 — 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 C4850C50ZN070500 — 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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