Same-day shipping before 3PM CST · 35,000+ OEM Parts · Texas CMBL & SAM.gov Registered · Government POs Accepted

Menu

Home Shop All Account Cart
OEM Carrier Transformer 120V to 24V 40VA for U19X100U36A
Carrier

OEM Carrier Transformer 120V to 24V 40VA for U19X100U36A

SKU: CARRIE-U19X100U36A-TRANSFORMER-HT01CN001 Brand: Carrier
✓ Guaranteed to fit U19X100U36A — or your money back. Terms

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

OEM Carrier Control Transformer 120V to 24V 40VA for Model U19X100U36A

This OEM Carrier transformer (part #HT01CN001) is the factory-specified replacement for the Carrier U19X100U36A HVAC system. The transformer steps down 120V line voltage to a safe 24V (with a 12V tap) at 40VA to power all low-voltage control circuits — including the thermostat, control board signals, and relay coils. When it fails, the entire control circuit goes dark: the thermostat loses power, the system refuses to respond to any command, or you may detect a faint buzzing or burning smell near the air handler cabinet.

  • Specs: 120V Primary | 24V / 12V Secondary | 40VA Rating | OEM Part #HT01CN001 | Replaces legacy part numbers HT01BJ115, 19EA41612, and 19EA42612
  • OEM vs Generic: This is the genuine Carrier factory part — not an aftermarket substitute. OEM transformers are wound to exact VA and voltage tolerances, ensuring your control board and thermostat operate within safe design parameters. Generic alternatives can run outside tolerance, causing nuisance trips or premature board failure.
  • Install difficulty: 3/5 — Requires disconnecting 120V line power at the breaker before any work begins. Tools needed: multimeter (to confirm 0V before touching terminals), flat-head and Phillips screwdrivers, wire stripper, needle-nose pliers, and wire nuts or terminal connectors. Always label or photograph all low-voltage wiring before disconnecting. Verify secondary output voltage after installation before restoring full system power.
  • Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse on all in-stock orders placed before cut-off.

Compatibility: Factory-matched for Carrier model U19X100U36A. Confirm your existing transformer's primary voltage (120V), secondary voltage (24V/12V), and VA rating (40VA) against your unit's data plate before ordering — incorrect VA ratings can overload the transformer under full control-circuit load. Have a question about fitment? Our HVAC parts specialists verify compatibility before you order.

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 U19X100U36A?
Yes. This is the factory-specified OEM transformer for the Carrier U19X100U36A. 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 U19X100U36A?
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.
Home Shop Search Account Cart
Fitment Guaranteed
MR
Mike Rivera
HVAC Parts Specialist — Online