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OEM Carrier Transformer 40VA 208/240V–24V for PY3GPAA42090AA
Carrier

OEM Carrier Transformer 40VA 208/240V–24V for PY3GPAA42090AA

SKU: CARRIE-PY3GPAA42090AA-TRANSFORMER-HT01BD209 Brand: Carrier
✓ Guaranteed to fit PY3GPAA42090AA — or your money back. Terms

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Texas CMBL #19328542014
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OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3GPAA42090AA

This OEM Carrier control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY3GPAA42090AA HVAC system. The transformer steps down line voltage from 208/240V to the 24V signal used by your thermostat, control board, and all low-voltage components. When it fails, the entire control circuit goes dark — no thermostat response, no fan, no heat or cool — making it one of the first components to check during a no-call diagnostic.

  • Specs: 208/240V Primary | 24V Secondary | 40VA Capacity | 50/60Hz | OEM Part # HT01BD209 | Replaces HT01BD207, HT01CN232, 9076-00
  • OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Undersized or off-spec aftermarket transformers can sag under load, causing intermittent resets, nuisance tripped breakers, or premature control board failure.
  • Install Difficulty: 2/5 — Shut off power at the breaker and disconnect the furnace disconnect before starting. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade terminals. Label all wires before disconnecting. Confirm secondary output reads ~24–28VAC under load after installation.
  • Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse.

Compatibility: Designed for the Carrier PY3GPAA42090AA HVAC system. Also cross-references HT01BD207, HT01CN232, and 9076-00. Always verify primary voltage (208V or 240V) on your unit's data plate before ordering. Not sure if it fits? Contact our parts team — we verify fitment 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 $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 PY3GPAA42090AA?
Yes. This is the factory-specified OEM transformer for the Carrier PY3GPAA42090AA. 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 PY3GPAA42090AA?
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
HVAC Parts Specialist — Online