OEM Carrier Transformer 40VA 120V/24V for Model GA2AAD036071ACJA

This OEM replacement transformer (part# HT01BC116) is the factory-specified control circuit transformer for the Carrier GA2AAD036071ACJA split-system unit. The transformer steps down line voltage from 120V to the 24V signal required by your thermostat, control board, contactor coil, and all low-voltage system controls. When it fails, the entire control circuit goes dark — your thermostat loses power, the system refuses to respond to any calls for heating or cooling, and nothing works. If you're getting 120V at the primary but zero volts at the secondary, this transformer is your fix.

• Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01BC116 | Factory-matched output for full control circuit stability
• OEM vs Generic: The OEM HT01BC116 transformer is wound and tested to Carrier's exact VA and voltage tolerances. Undersized or off-spec generic transformers can brown out under full control circuit load, causing erratic lockouts, nuisance tripping, and premature contactor coil failure.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, wire stripper, multimeter. Label or photograph all wiring connections before disconnecting. Verify 0V at primary terminals with your multimeter before handling.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. In-stock units ship same business day from our warehouse.

Compatibility: Designed for the Carrier GA2AAD036071ACJA (3-ton, R-410A). Always confirm your existing transformer's VA rating and primary/secondary voltages on the unit data plate or wiring diagram before ordering — substituting a lower VA-rated transformer into a multi-zone or multi-component circuit can cause immediate overload. Our fitment team is available to verify compatibility before you buy.