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OEM Payne Transformer 40VA 120V-24V for PA3ZNB042000AB
Payne

OEM Payne Transformer 40VA 120V-24V for PA3ZNB042000AB

SKU: PAYNE-PA3ZNB042000AB-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 Control Transformer 40VA 120V/24V for Model PA3ZNB042000AB

This OEM replacement transformer (Part# HT01BD209) is the factory-specified control circuit transformer for the Payne PA3ZNB042000AB split-system air conditioner. The transformer steps down line voltage from 120V to the 24V AC required to power your thermostat, contactor coil, and all low-voltage control circuits. When the transformer fails, the entire control system loses power — the thermostat goes blank, the system won't respond to any calls for heating or cooling, and no safety safeties or relays can operate. A failed transformer is often misdiagnosed as a bad control board or thermostat, so always verify 24V output at the secondary terminals before replacing other components.

  • Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Factory-matched OEM part for Payne PA3ZNB042000AB | OEM Part Number: HT01BD209
  • OEM vs Generic: This is a genuine OEM transformer built to Payne's exact VA and voltage tolerances. Generic transformers frequently underperform under full control-circuit load, causing intermittent brownouts that damage contactors and control boards over time.
  • Install difficulty: 2/5 — Shut off all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, wire nuts. Note wire colors and terminal positions before disconnecting. Confirm 24V output with a multimeter after installation before restoring full system power.
  • Warranty: 1-year OEM factory warranty against defects. Orders placed before cutoff ship same business day from our climate-controlled warehouse.

Compatibility: Engineered specifically for the Payne PA3ZNB042000AB split-system unit. Verify your existing transformer's VA rating and primary/secondary voltages on the data plate before ordering to ensure a correct fit. Our HVAC parts specialists are available to confirm compatibility before you buy — no guesswork required.

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 PA3ZNB042000AB?
Yes. This is the factory-specified OEM transformer for the Payne PA3ZNB042000AB. 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 PA3ZNB042000AB?
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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