OEM Carrier 40VA Control Transformer for Model U19X125U60A

This is the factory OEM replacement transformer (part number HT01CN001) for the Carrier U19X125U60A. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, and all low-voltage switching circuits. When this component fails, the entire control circuit goes dark — resulting in a blank thermostat display, no response to heating or cooling calls, or repeated control board faults with no apparent cause. Replacing the transformer with the correct OEM unit immediately restores reliable 24V power to every downstream component.

• Specs: 120V primary → 24V secondary | 40VA rated | Factory-matched impedance and thermal protection | Designed for Carrier U19X125U60A control circuit
• OEM vs Generic: OEM transformers are wound and insulated to exact Carrier factory tolerances, ensuring stable 24V output under full load. Generic units can sag under load voltage, causing nuisance lockouts, intermittent control failures, and premature board damage.
• Install difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Always label low-voltage wires before removal.
• Warranty: 1-year OEM factory warranty included. Orders ship same business day from our NationalHVACParts.com warehouse.

Compatibility: Engineered specifically for the Carrier U19X125U60A. Always verify your unit's control voltage and VA rating on the equipment data plate before ordering. Have a question about fitment? Our HVAC parts specialists confirm compatibility before you buy — order with confidence.