Same-day shipping before 3PM CST · 35,000+ OEM Parts · Texas CMBL & SAM.gov Registered · Government POs Accepted

Menu

Home Shop All Account Cart
OEM Carrier Transformer 40VA 120V to 24V for C4850C48ZN040200 — Ships Today
Carrier

OEM Carrier Transformer 40VA 120V to 24V for C4850C48ZN040200 — Ships Today

SKU: CARRIE-C4850C48ZN040200-TRANSFORMER-HT01BD236 Brand: Carrier

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

OEM Carrier Transformer 40VA 120V to 24V for Model C4850C48ZN040200

This OEM replacement transformer (part number HT01BD236) is the factory-specified control circuit transformer for the Carrier C4850C48ZN040200 packaged unit. Its job is to step down line voltage (120V) to the 24V signal voltage that powers your thermostat, control board, contactor coil, and every other low-voltage component in the system. When this transformer fails, nothing works — the thermostat goes blank, the system won't respond to any call for heating or cooling, and you may find a blown 3A fuse on the control board as a secondary symptom.

  • Specs: 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01BD236 | Factory-matched footprint and lead configuration for direct drop-in replacement
  • OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances required by the Carrier control board. Undersized or off-tolerance generic units can cause nuisance tripping, control board damage, or repeated fuse failures — making OEM the only reliable long-term choice.
  • Install difficulty: 2/5 — Disconnect all power before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Confirm secondary voltage (should read 24–28V AC) after installation before restoring full power. Label or photograph all wiring connections prior to removal.
  • Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier C4850C48ZN040200 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltages against your unit's data plate before ordering. If you're unsure of fitment, our technical team is available to confirm compatibility before you buy — same-day shipping means your system is back online fast.

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 C4850C48ZN040200 — Ships Today?
Yes. This is the factory-specified OEM transformer for the Carrier C4850C48ZN040200 — 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 C4850C48ZN040200 — 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.
Home Shop Search Account Cart
Fitment Guaranteed
MR
Mike Rivera
HVAC Parts Specialist — Online