OEM Carrier Control Transformer 120V/24V 40VA for Model PH12NA030000ACAA

This is the OEM factory-replacement control transformer (part number HT01AW229) for the Carrier PH12NA030000ACAA packaged heat pump unit. The transformer steps down line voltage (120V) to the 24V AC signal that powers the entire low-voltage control circuit — including the thermostat, contactor coil, reversing valve, and control board. When this transformer fails, the result is total system non-response: the thermostat goes blank or unresponsive, and neither heating nor cooling will initiate. A blown 3A fuse on the secondary side is often the first clue that the transformer has failed or is being overloaded by a wiring fault.

• Specs: Primary voltage: 120V AC | Secondary voltage: 24V AC | VA rating: 40VA | OEM part number: HT01AW229 | Factory-matched windings and insulation class
• OEM vs Generic: This OEM transformer is wound to Carrier's exact VA rating and insulation specification. Generic substitutes frequently use undersized cores that run hot under peak demand, shortening service life and risking secondary fuse failure during high-load conditions.
• Install difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter (verify 24V output after install), wire nuts or push-in connectors. Always check for downstream short circuits before replacing — a shorted control wire will blow the new transformer immediately.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Engineered as a direct OEM drop-in for the Carrier PH12NA030000ACAA packaged heat pump. Verify your unit's data plate lists 120V primary control voltage before ordering. If your system runs on 208/240V primary, a different transformer part number is required — contact our fitment team to confirm before purchase. We verify compatibility so you get the right part the first time.