OEM Carrier 40VA Control Transformer HT01AW229 for Model PH13NR024000AHAA

This OEM control transformer (part# HT01AW229) is the factory-specified replacement for the Carrier PH13NR024000AHAA heat pump system. The transformer steps down 120V line voltage to the 24V signal required by the thermostat, contactor coil, and control board. When this component fails, the entire 24V control circuit goes dark — the thermostat becomes unresponsive, the system will not call for heating or cooling, and no components will energize. It is one of the first parts to check when an otherwise healthy system shows zero response to thermostat input.

• Specs: 120V primary → 24V secondary | 40VA rated output | Factory-matched windings | Matches original OEM footprint and mounting for drop-in installation
• OEM vs Generic: This is the genuine OEM Carrier part (HT01AW229), manufactured to exact factory specifications. Generic transformers are often under-rated in VA, leading to voltage sag under load, nuisance tripping, and premature failure — especially in multi-zone or communicating thermostat systems.
• Install Difficulty: 2/5 — Shut off power at the disconnect and confirm 0V with a multimeter before proceeding. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Note and photograph all 24V wiring terminal connections before disconnecting. Test output voltage after installation prior to re-energizing the full system.
• Warranty: 1-year OEM factory warranty. Ships same business day from our stocked warehouse.

Compatibility: Engineered for the Carrier PH13NR024000AHAA heat pump. Always verify your existing transformer's primary voltage, secondary voltage, and VA rating against your unit's data plate before ordering. Our fitment team is available to confirm compatibility before you buy — contact us with your model and serial number.