What are the specs for this Transformer?

The correct replacement for Carrier model PY3PNA024040AA 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 PY3PNA024040AA.

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 Transformer 40VA 208/240V–24V for PY3PNA024040AA

Name: OEM Carrier Transformer 40VA 208/240V–24V for PY3PNA024040AA
Brand: Carrier
SKU: CARRIE-PY3PNA024040AA-TRANSFORMER-HT01BD209
Price: 47.25 USD
Availability: InStock

SKU: CARRIE-PY3PNA024040AA-TRANSFORMER-HT01BD209 Brand: Carrier

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OEM Carrier Control Transformer 40VA 208/240V to 24V — Model PY3PNA024040AA

This OEM Carrier transformer (part #HT01BD209) is the factory-specified control transformer for the Carrier PY3PNA024040AA packaged HVAC unit. Its job is critical and simple: step down the 208/240V line voltage to the 24V low-voltage signal used by your thermostat, control board, contactor coil, and every other control-circuit component. When this transformer fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to any call for heating or cooling, and a multimeter at the secondary terminals will read zero volts instead of 24V.

Specs: Input 208/240V | Output 24V | 40VA power rating | 50/60Hz | Factory OEM part #HT01BD209 | Direct drop-in fit for PY3PNA024040AA
OEM vs Generic: OEM transformers are wound and potted to Carrier's exact tolerances. Generic aftermarket units often run outside ±5% output voltage, which can cause nuisance lockouts, erratic board behavior, and premature contactor coil failure.
Install Difficulty: 2/5 — Shut off power at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Photograph or label all low-voltage wire connections before removing the old unit. Verify 24V at secondary terminals after reinstall before closing the panel.
Warranty: 1-year OEM factory warranty included. In-stock and ships same business day from our warehouse.

Compatibility: Engineered for the Carrier PY3PNA024040AA packaged unit. Also fits additional Carrier, Bryant, and Payne models that specify the HT01BD209 control transformer — verify your unit's model and data plate before ordering. Not sure? Our HVAC parts specialists confirm fitment at no charge before you buy. Order today and get same-day shipping on all in-stock parts.

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 Transformer 40VA 208...

$47.25

Frequently Asked Questions

Does this Transformer fit my Carrier PY3PNA024040AA?

Yes. This is the factory-specified OEM transformer for the Carrier PY3PNA024040AA. 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 PY3PNA024040AA?

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 Transformer 40VA 208/240V–24V for PY3PNA024040AA

OEM Carrier Control Transformer 40VA 208/240V to 24V — Model PY3PNA024040AA

Shipping Information

Return Policy

Frequently Asked Questions