OEM Carrier Control Transformer 120V/24V 40VA for Model PH10JA036000ACAA

This is the factory OEM replacement transformer (part number HT01AW229) designed specifically for the Carrier PH10JA036000ACAA packaged heat pump unit. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, contactor coil, and every other low-voltage component in the system. When this transformer fails, the entire control circuit goes dead — the thermostat loses power, the unit will not respond to any call for heating or cooling, and no safety safeties or relays will energize. If your system is completely unresponsive and you have confirmed 120V at the unit but 0V on the 24V secondary, this transformer is the most likely culprit.

• Specs: 120V primary | 24V secondary | 40VA rated | Factory-spec wire leads | Designed to OEM tolerances for PH10JA036000ACAA
• OEM vs Generic: This is the genuine Carrier OEM part (HT01AW229), manufactured to exact VA and voltage tolerances. Generic transformers often run under-rated VA, which can cause voltage sag under load, nuisance tripping, and premature failure of downstream controls.
• Install difficulty: 2/5 — Disconnect power at the breaker and verify zero voltage before touching any wiring. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or terminal connectors. Label or photograph all wiring connections before removal.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. In-stock and ships same business day from our warehouse.

Compatibility: Directly fits Carrier model PH10JA036000ACAA packaged heat pump units. Always verify your existing transformer's primary voltage, secondary voltage, and VA rating against the data plate inside the unit before ordering to confirm fitment. Need help? Our HVAC parts specialists verify compatibility before you buy — no guesswork.