OEM Carrier Transformer 120V–24V 40VA for Model PH13NB030000AAAA

This OEM control circuit transformer (part number HT01AW229) is the factory-specified replacement for the Carrier PH13NB030000AAAA heat pump system. The transformer steps down line voltage (120V) to the 24V signal voltage required to power the thermostat, control board, and all low-voltage safety and switching circuits. When the transformer fails, the entire control circuit goes dead — the thermostat goes blank, the system produces zero response to any call for heating or cooling, and no fault codes will display because the board itself has no power.

• Specs: Primary: 120V AC | Secondary: 24V AC | VA Rating: 40VA | OEM Part Number: HT01AW229 | Factory-matched for Carrier PH13NB030000AAAA heat pump systems
• OEM vs Generic: This is a genuine OEM Carrier transformer built to factory VA and voltage tolerances. Generic transformers frequently run outside rated VA capacity, causing overloads, nuisance trips, and shortened control board life — especially under heavy thermostat switching loads.
• Install difficulty: 2/5 — Shut off all power to the unit at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Label or photograph all low-voltage wiring connections before disconnecting. The transformer mounts to the control box and connects to the primary high-voltage side and the secondary 24V control wiring harness.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Engineered as a direct OEM replacement for the Carrier PH13NB030000AAAA heat pump. Always verify your unit's wiring diagram and existing transformer VA rating on the data plate or control box label before ordering. Our fitment team is available to confirm compatibility before you purchase — no guesswork required. In stock and ships today.