What are the specs for this Transformer?

The correct replacement for Carrier model PF4MNB043T00AAAA 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 PF4MNB043T00AAAA.

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 120V-24V for PF4MNB043T00AAAA

Name: OEM Carrier Transformer 40VA 120V-24V for PF4MNB043T00AAAA
Brand: Carrier
SKU: CARRIE-PF4MNB043T00AAAA-TRANSFORMER-HT01CN241
Price: 47.25 USD
Availability: InStock

SKU: CARRIE-PF4MNB043T00AAAA-TRANSFORMER-HT01CN241 Brand: Carrier

✓ Guaranteed to fit PF4MNB043T00AAAA — or your money back. Terms

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OEM Carrier Transformer 40VA 120V to 24V for Model PF4MNB043T00AAAA

This OEM replacement transformer (part number HT01CN241) is the factory-specified control circuit transformer for the Carrier PF4MNB043T00AAAA air handler. Its sole but critical job is to step line voltage (120V) down to 24V to power the low-voltage control circuit — including your thermostat, zone controls, and every relay on the board. When this transformer fails, nothing works: the thermostat goes dark, the system is completely unresponsive, and you may measure zero volts on the secondary side with a multimeter.

Specs: Input: 120V AC | Output: 24V AC | Rating: 40VA | OEM Part Number: HT01CN241 | Factory-matched insulation class and thermal protection
OEM vs Generic: This is the genuine Carrier OEM unit — built to exact VA and thermal cutout specifications. Generic transformers often run undersized VA ratings, causing premature burnout under normal load from thermostats and zone boards.
Install Difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Photograph and label all wiring connections before disconnecting the old unit. Verify 24V output on secondary terminals before closing the panel.
Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Designed and tested for the Carrier PF4MNB043T00AAAA air handler. Always confirm input voltage and VA rating on your unit's data plate before ordering — mismatched VA ratings will cause repeated transformer failure. Our fitment team is available to verify compatibility before you purchase.

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 120...

$47.25

Frequently Asked Questions

Does this Transformer fit my Carrier PF4MNB043T00AAAA?

Yes. This is the factory-specified OEM transformer for the Carrier PF4MNB043T00AAAA. 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 PF4MNB043T00AAAA?

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 120V-24V for PF4MNB043T00AAAA

OEM Carrier Transformer 40VA 120V to 24V for Model PF4MNB043T00AAAA

Shipping Information

Return Policy

Frequently Asked Questions