OEM Carrier Transformer 40VA 120V/24V for Model GA2AAD036055AAJA

This OEM replacement transformer (part # HT01BC116) is the factory-specified control circuit transformer for the Carrier GA2AAD036055AAJA packaged or split-system unit. The transformer steps down line voltage from 120V to 24V to power the low-voltage control circuit — including the thermostat, contactor coil, and control board. When this transformer fails, the entire control circuit goes dark: the thermostat becomes unresponsive, the system won't call for heating or cooling, and you may measure 0V at the R and C thermostat terminals even with power to the unit.

• Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01BC116 | Factory-matched windings and insulation class for long service life
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances required by the Carrier GA2AAD036055AAJA control circuit. Undersized or off-tolerance generic units can overheat, trip the internal fuse, or cause erratic thermostat behavior — often misdiagnosed as a bad control board.
• Install difficulty: 2/5 — Shut off all power before beginning. Tools needed: flat-head and Phillips screwdrivers, multimeter, needle-nose pliers. Label and photograph all low-voltage wiring before disconnecting. Verify 0V at primary leads with a multimeter before touching any terminals.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our stocked warehouse when ordered before 3 PM local time.

Compatibility: Designed as a direct OEM replacement for Carrier model GA2AAD036055AAJA. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate or existing transformer label before ordering. Not sure if this is your part? Our HVAC parts specialists confirm fitment before you buy — no guesswork, no returns.