OEM Carrier 40VA Control Transformer HT01BC116 for Model GB3AAV024050AFJA

This OEM replacement transformer (part number HT01BC116) is the factory-specified control circuit transformer for the Carrier GB3AAV024050AFJA gas furnace. The transformer steps down line voltage from 120V to the 24V signal voltage required to power the thermostat, control board, gas valve, and all low-voltage switching components. When this transformer fails, the entire control circuit goes dark — the thermostat displays nothing, the inducer never starts, and the system will not attempt ignition. A failed transformer is one of the most common causes of a completely unresponsive furnace and is often misdiagnosed as a control board failure.

• Specs: 40VA rated | 120V primary / 24V secondary | Class 2 control circuit transformer | Direct OEM replacement for part number HT01BC116 | Exceeds UL listed requirements
• OEM vs Generic: This OEM unit is wound to Carrier's exact VA rating and insulation class. Generic transformers often underrate their true VA capacity, causing thermal overload trips and premature failure — especially in systems with multiple 24V accessories such as humidifiers, zone boards, or communicating thermostats.
• Install difficulty: 2/5 — Disconnect power at the breaker and verify zero voltage with a multimeter before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper. Label or photograph all low-voltage wiring connections before disconnecting. Replace any blown 3A fuse on the control board at the same time.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier GB3AAV024050AFJA gas furnace. Always verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate or wiring diagram before ordering. If your system includes a whole-home humidifier or multiple zone controllers, confirm the 40VA rating meets your total low-voltage load. Our fitment team is available to verify compatibility before you order — in stock and ships today.