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OEM Carrier Control Transformer 40VA 208/240V–24V for PY3GNA030040AB
Carrier

OEM Carrier Control Transformer 40VA 208/240V–24V for PY3GNA030040AB

SKU: CARRIE-PY3GNA030040AB-TRANSFORMER-HT01BD209 Brand: Carrier
✓ Guaranteed to fit PY3GNA030040AB — or your money back. Terms

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3GNA030040AB

This OEM Carrier control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY3GNA030040AB packaged unit. The transformer steps down high-voltage line power (208/240V) to the 24V DC signal required by the control circuit — powering the thermostat, contactor coil, and every low-voltage control component in the system. When it fails, the entire control circuit goes dark: the thermostat becomes unresponsive, the unit will not start, and no fault codes will display on the board. A failed transformer is often misdiagnosed as a control board failure, making correct identification critical before ordering replacement parts.

  • Specs: 208/240V primary input | 24V secondary output | 40VA power rating | 50/60Hz | Factory-matched OEM tolerances for the Carrier PY3GNA030040AB
  • OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances. Undersized or off-spec generic units can cause erratic thermostat behavior, nuisance tripping of the low-voltage fuse, or premature contactor coil failure.
  • Install difficulty: 2/5 — Always shut off all power to the unit at the disconnect before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter (to verify 24V output after installation), wire nuts or spade connectors. Photograph all wiring before disconnecting terminals. Test for 24V output and check the low-voltage fuse before condemning the transformer.
  • Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed as a direct OEM replacement for Carrier model PY3GNA030040AB. Verify primary voltage on your unit's data plate (208V or 240V configurations) before ordering. Not sure this is the right part? Our HVAC parts specialists verify fitment before you order — contact us today and get your system 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 $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 PY3GNA030040AB?
Yes. This is the factory-specified OEM transformer for the Carrier PY3GNA030040AB. 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 PY3GNA030040AB?
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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