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 PH4GPXB42000AA
Carrier

OEM Carrier Transformer 75VA 208/240/480V–24V for PH4GPXB42000AA

SKU: CARRIE-PH4GPXB42000AA-TRANSFORMER-HT01BD242 Brand: Carrier

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 to 24VAC — Model PH4GPXB42000AA

This is the genuine OEM replacement control transformer (Part #HT01BD242) for the Carrier PH4GPXB42000AA packaged unit. The transformer steps down high line voltage (208/240/480V primary) to the 24VAC signal that powers your thermostat, contactor coil, and control board. When the transformer fails, the entire low-voltage control circuit goes dead — your thermostat goes blank, the system refuses to respond to any call for heating or cooling, and fuses or breakers may trip repeatedly. Replacing it restores full control circuit operation immediately.

  • Specs: 75VA capacity | 208/240/480V primary | 24VAC secondary | 50/60Hz | Foot-mount configuration | OEM Part #HT01BD242
  • OEM vs Generic: OEM transformers are wound to exact factory VA ratings and insulation class, ensuring the full 24V signal under load. Undersized or off-spec generic units can sag voltage under peak demand, causing erratic contactor chatter and nuisance lockouts.
  • Install difficulty: 2/5 — Shut off all power to the unit at the disconnect before starting. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Photograph all wiring connections before removing the old transformer. Confirm primary voltage tap matches your supply voltage before energizing.
  • Warranty: 1-year OEM factory warranty. In-stock units ship same business day from our warehouse.

Compatibility: Factory-specified replacement for Carrier model PH4GPXB42000AA packaged units. Also fits a range of Carrier, Bryant, and ICP family equipment using the HT01BD242 transformer. Always verify your unit's supply voltage (208V, 240V, or 480V) against the primary tap setting before installation. Questions about fitment? Our parts specialists confirm compatibility before you order — no guesswork.

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 PH4GPXB42000AA?
Yes. This is the factory-specified OEM transformer for the Carrier PH4GPXB42000AA. 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 PH4GPXB42000AA?
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