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OEM Payne Transformer 40VA 120V-24V for PA3ZNA042000AA
Payne

OEM Payne Transformer 40VA 120V-24V for PA3ZNA042000AA

SKU: PAYNE-PA3ZNA042000AA-TRANSFORMER-HT01BD209 Brand: Payne

Order before 3PM CST — ships same day.
Standard delivery 2-5 business days. Express options at checkout.

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OEM Payne 40VA Control Transformer for Model PA3ZNA042000AA

This is the factory OEM replacement transformer for the Payne PA3ZNA042000AA packaged air conditioning unit. The transformer steps down 120V line voltage to the 24V signal voltage that powers your thermostat, control board, contactor coil, and all low-voltage system controls. When this transformer fails — whether from a wiring short, age, or voltage spike — the entire control circuit goes silent: the thermostat goes blank, the system won't respond to any calls for cooling or heating, and no safety or diagnostic lights illuminate on the board.

  • Specs: 40VA output rating | Primary: 120V | Secondary: 24V | OEM part number HT01BD209 | Factory-matched for PA3ZNA042000AA
  • OEM vs Generic: This OEM unit is wound and insulated to Payne's exact factory specification. Generic transformers often carry marginal VA ratings that sag under full control-circuit load, causing nuisance lockouts and shortened board life.
  • Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire nuts or spade connectors, multimeter to verify 24V output after installation. Label all wires before disconnecting the old unit.
  • Warranty: 1-year OEM factory warranty. Orders placed by 3 PM ship same business day from our climate-controlled warehouse.

Compatibility: Designed specifically for the Payne PA3ZNA042000AA packaged unit. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering. Our HVAC parts specialists are available to confirm fitment — call or chat before you buy.

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 support@nationalhvacparts.com to initiate a return
  • Refunds processed within 5-7 business days

Frequently Asked Questions

Does this Transformer fit my Payne PA3ZNA042000AA?
Yes. This is the factory-specified OEM transformer for the Payne PA3ZNA042000AA. 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 Payne PA3ZNA042000AA?
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 Payne 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 Payne 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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