OEM Carrier 40VA Control Transformer HT01BC116 for Model GB3AAV048115AEJA

This is the factory OEM replacement transformer (part# HT01BC116) for the Carrier GB3AAV048115AEJA gas furnace. The transformer steps down 120V line voltage to 24V AC to power the entire low-voltage control circuit — including the thermostat, control board, gas valve, and safety switches. When the transformer fails, the result is total system shutdown: the thermostat goes blank, nothing responds, and no heating cycle can begin. A failed transformer is often misdiagnosed as a bad control board, making correct identification critical before replacing more expensive components.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Direct OEM replacement for Carrier part# HT01BC116 | Factory-matched electrical tolerances
• OEM vs Generic: OEM transformers are wound and insulated to Carrier's exact specifications, ensuring stable 24V output under full control circuit load. Generic units often deliver inconsistent voltage that can cause nuisance lockouts, erratic board behavior, or premature contactor failure.
• Install difficulty: 2/5 — Disconnect power at the breaker and verify voltage is off before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Confirm secondary output reads 24–28V AC after install before restoring full system operation.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier GB3AAV048115AEJA gas furnace. Always verify your existing transformer's VA rating and primary/secondary voltages against your unit's wiring diagram before ordering. Our fitment team is available to confirm compatibility before you purchase — just ask.