OEM Carrier Control Transformer 120V to 24V 40VA — HT01CN001 for Model U19X125U60B

The Carrier HT01CN001 is the factory-specified OEM control transformer for the U19X125U60B unit. Its job is critical: it steps down 120V line voltage to the 24V signal voltage that powers your thermostat, control board, and every low-voltage relay in the system. When this transformer fails, the entire control circuit goes dark — the thermostat loses power, the system won't respond to any call for heating or cooling, and you may hear a faint hum or buzz from the transformer itself. Replacing it with the correct OEM part restores full factory functionality immediately.

• Specs: 120V Primary | 24V/12V Secondary | 40VA Rating | Foot-mount configuration | Factory Authorized Part (replaces HT01BJ115, 19EA41612, 19EA42612)
• OEM vs Generic: This is a genuine Carrier OEM transformer engineered to exact VA ratings and insulation class for the U19X125U60B. Aftermarket transformers are often underrated in VA capacity, leading to thermal overload and premature failure under full control-circuit load.
• Install Difficulty: 2/5 — Shut off all power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire labels. Always label and photograph all 24V low-voltage wiring before disconnecting. Verify input and output voltages with a meter after installation before restoring full system power.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Directly fits Carrier model U19X125U60B. Confirm primary voltage (120V) and VA rating (40VA) on your unit's data plate before ordering. If you are unsure of fitment, our HVAC parts team verifies compatibility before you place your order — no guesswork, no returns.