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OEM Carrier Control Transformer 40VA 208/240V–24V — PY3GNAA24040AA
Carrier

OEM Carrier Control Transformer 40VA 208/240V–24V — PY3GNAA24040AA

SKU: CARRIE-PY3GNAA24040AA-TRANSFORMER-HT01BD209 Brand: Carrier
✓ Guaranteed to fit PY3GNAA24040AA — or your money back. Terms

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Texas CMBL #19328542014
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OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3GNAA24040AA

This is the factory OEM control transformer for the Carrier PY3GNAA24040AA packaged unit, identified by part number HT01BD209. The transformer steps down line voltage (208/240V) to the 24V signal that powers your thermostat, control board, contactor coil, and every other low-voltage component in the system. When it fails, the result is complete loss of control circuit function — a blank thermostat, a system that won't respond to any call for heating or cooling, or a tripped secondary fuse caused by a shorted low-voltage circuit.

  • Specs: 40VA | 208/240V primary | 24V secondary | 50/60 Hz | Replaces HT01BD207, HT01CN232 & 9076-00
  • OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances. Undersized or off-tolerance aftermarket units can overheat, blow fuses repeatedly, or damage sensitive control boards over time.
  • Install difficulty: 2/5 — De-energize the unit at the disconnect before starting. Tools needed: multimeter (verify 0V at transformer terminals), flathead and Phillips screwdrivers, wire nuts or spade connectors. Always confirm primary and secondary wiring polarity matches the old unit before powering back up.
  • Warranty: 1-year OEM factory warranty. Same-business-day shipping from our warehouse stock.

Compatibility: Direct OEM replacement for Carrier PY3GNAA24040AA packaged units. Verify existing transformer VA rating and primary voltage on your unit's data plate before ordering. Cross-references: HT01BD207, HT01CN232, 9076-00. Need help confirming fitment? Our team checks compatibility before you order — ships 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 OEM Carrier Control Transformer 40VA 208/240V–24V — PY3GNAA24040AA?
Yes. This is the factory-specified OEM transformer for the Carrier OEM Carrier Control Transformer 40VA 208/240V–24V — PY3GNAA24040AA. 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 OEM Carrier Control Transformer 40VA 208/240V–24V — PY3GNAA24040AA?
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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