What are the specs for this Transformer?

The correct replacement for Carrier model PY4GNAA60090AA is this exact part. It is the factory-specified replacement with exact OEM specifications. Using a part with different specifications can cause equipment damage or void your warranty. You can verify this by checking the data plate on your Carrier equipment which lists the model number PY4GNAA60090AA.

Is this transformer compatible with Bryant or Payne systems too?

Many Carrier parts are cross-compatible with Bryant and Payne systems since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across multiple brand labels with different model numbers. To verify cross-compatibility, check your Bryant or Payne equipment service manual for cross-compatible part numbers, or contact info@nationalhvacparts.com with your model number for confirmation.

Carrier

OEM Carrier Control Transformer 40VA 208/240V–24V for PY4GNAA60090AA

Name: OEM Carrier Control Transformer 40VA 208/240V–24V for PY4GNAA60090AA
Brand: Carrier
SKU: CARRIE-PY4GNAA60090AA-TRANSFORMER-HT01BD209
Price: 47.25 USD
Availability: InStock

SKU: CARRIE-PY4GNAA60090AA-TRANSFORMER-HT01BD209 Brand: Carrier

✓ Guaranteed to fit PY4GNAA60090AA — or your money back. Terms

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OEM Carrier Control Transformer 40VA 208/240V to 24V — HT01BD209 for Model PY4GNAA60090AA

This genuine OEM Carrier control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY4GNAA60090AA packaged unit. The transformer steps down line voltage (208/240V primary) to a safe 24V secondary signal that powers your thermostat, control board, and all low-voltage control circuitry. When this transformer fails, the entire control circuit loses power — resulting in a completely unresponsive system: the thermostat goes blank, no heating or cooling stages activate, and no error codes are displayed because the board itself has no power to communicate.

Specs: 208/240V Primary | 24V Secondary | 40VA rating | 50/60 Hz | OEM part # HT01BD209 | Replaces HT01BD207, HT01CN232, and 9076-00
OEM vs Generic: OEM transformers are wound to exact VA and impedance tolerances required by Carrier's control board. Undersized or off-tolerance generic transformers can cause nuisance tripping, control board brownouts, or accelerated board failure — always use OEM when the control board is involved.
Install difficulty: 2/5 — Shut off power at the disconnect before beginning. Tools needed: multimeter (to verify 0V before touching wiring), flathead and Phillips screwdrivers, needle-nose pliers, wire nuts or spade terminals. Photograph all wiring before disconnecting. Verify 24V output at secondary terminals before reassembling the unit.
Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Factory-matched for Carrier model PY4GNAA60090AA packaged unit. Always verify your unit's data plate voltage matches 208/240V primary input before ordering. Cross-references: HT01BD207, HT01CN232, 9076-00, 4000A46E07AE28. Questions about fitment? Our HVAC parts team confirms compatibility before you order — reach out before purchasing.

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

OEM Carrier Control Transformer ...

$47.25

Frequently Asked Questions

Does this Transformer fit my Carrier PY4GNAA60090AA?

Yes. This is the factory-specified OEM transformer for the Carrier PY4GNAA60090AA. 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 PY4GNAA60090AA?

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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OEM Carrier Control Transformer 40VA 208/240V–24V for PY4GNAA60090AA

OEM Carrier Control Transformer 40VA 208/240V to 24V — HT01BD209 for Model PY4GNAA60090AA

Shipping Information

Return Policy

Frequently Asked Questions