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 75VA 208/240/480V–24V for PH3GNAA42000AA
Carrier

OEM Carrier Transformer 75VA 208/240/480V–24V for PH3GNAA42000AA

SKU: CARRIE-PH3GNAA42000AA-TRANSFORMER-HT01BD242 Brand: Carrier
✓ Guaranteed to fit PH3GNAA42000AA — or your money back. Terms

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

OEM Carrier Control Transformer 75VA 208/240/480V–24V for Model PH3GNAA42000AA

This is the genuine OEM Carrier replacement transformer (part #HT01BD242) factory-specified for the Carrier PH3GNAA42000AA packaged unit. The transformer steps down high-voltage primary power (208/240/480V) to the 24VAC secondary voltage that energizes the entire control circuit — including the thermostat, contactor coil, gas valve, and control board. When the transformer fails, the result is total loss of control: the thermostat goes dark, the system will not respond to any call for heating or cooling, and no safety circuit can function. It is often the first component to inspect when nothing works at all.

  • Specs: 75VA rating | Primary: 208/240/480VAC | Secondary: 24VAC | 50/60Hz | Foot-mount configuration | OEM part #HT01BD242
  • OEM vs Generic: This factory-authorized OEM transformer is wound to Carrier's exact VA rating and insulation class. Undersized or off-tolerance aftermarket transformers overheat under real-world load, causing nuisance tripping or premature failure of the control board.
  • Install difficulty: 3/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: multimeter (verify 0V before touching terminals), flathead and Phillips screwdrivers, wire stripper, and electrical tape. Label all wires before removal. Verify primary voltage matches your supply before energizing.
  • Warranty: 1-year OEM factory warranty. In-stock units ship same business day from our warehouse.

Compatibility: Engineered as the direct OEM replacement for the Carrier PH3GNAA42000AA packaged unit. Compatible across Carrier, Bryant, Payne, Tempstar, and Heil systems that specify HT01BD242. Always confirm primary voltage (208/240/480V) and VA rating (75VA) against your unit's data plate before ordering. Our HVAC 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 PH3GNAA42000AA?
Yes. This is the factory-specified OEM transformer for the Carrier PH3GNAA42000AA. 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 PH3GNAA42000AA?
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