OEM Carrier Control Transformer 40VA 120V–24V for Model PH4GEXA60000AA

This OEM replacement transformer (part number HT01BC701) is the factory-specified step-down transformer for the Carrier PH4GEXA60000AA packaged heat pump unit. Its primary function is to convert 120V line voltage to the 24V AC control-circuit voltage required to power your thermostat, contactor coils, and control board. When this transformer fails, the entire low-voltage control circuit goes dead — your thermostat goes blank, nothing responds, and the system will not operate in any mode.

• Specs: 40VA rating | 120V primary / 24V secondary | Class 2 transformer | Factory-matched OEM tolerances for stable, consistent control-circuit voltage
• OEM vs Generic: OEM transformers from Carrier maintain tight voltage regulation under full VA load, protecting sensitive control boards and thermostat circuitry. Generic units are prone to voltage sag under load, which can cause erratic system behavior or premature board failure.
• Install Difficulty: 2/5 — Always shut off power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, wire stripper, and a multimeter to confirm 24V output after installation. Label or photograph all wiring connections before removal.
• 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 drop-in replacement for the Carrier PH4GEXA60000AA packaged heat pump unit. Always verify the part number on your existing transformer's label before ordering. Our HVAC parts specialists are available to confirm fitment — order with confidence and get your system back online fast.