OEM Carrier Control Transformer 40VA for Model GA1AAD048070AAJA

This is the factory OEM replacement control transformer (part number HT01BC116) for the Carrier GA1AAD048070AAJA packaged unit. The transformer steps down 120V line voltage to the 24V signal required by your thermostat, control board, contactor coil, and all safety circuits. When this component fails, the entire control circuit goes dark — the thermostat becomes unresponsive, the system won't call for heating or cooling, and no safety lockout codes appear because there's no power to generate them. A failed transformer is often the first suspect when a unit is completely unresponsive despite confirmed line voltage at the disconnect.

• Specs: 40VA rating | 120V primary / 24V secondary | Factory-matched impedance and thermal protection | OEM part number HT01BC116
• OEM vs Generic: The OEM HT01BC116 transformer is wound to Carrier's exact VA rating and insulation class. Undersized or off-spec generic transformers can overheat under full control-circuit load, tripping thermal cutoffs repeatedly or failing prematurely — especially in systems with zone controllers or accessories drawing additional 24V power.
• Install difficulty: 2/5 — Shut off all power at the disconnect before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, wire stripper, multimeter. Confirm 0V at primary terminals before handling. Photograph all wiring connections before removal and match wire gauge on reinstallation.
• Warranty: 1-year OEM factory warranty. In-stock units ship same business day from our warehouse when ordered before cutoff.

Compatibility: Designed specifically for the Carrier GA1AAD048070AAJA packaged unit. Always verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate or wiring diagram before ordering. Our HVAC parts specialists are available to confirm fitment — reach out before you order if you have any questions.