OEM Carrier Transformer 40VA 120V/24V for Model GB1AAV036045AFJA

This OEM step-down transformer (part number HT01BC116) is the factory-specified replacement for the Carrier GB1AAV036045AFJA gas furnace. The transformer converts 120V line voltage down to 24V AC to power the entire low-voltage control circuit — including the thermostat, control board, gas valve, and inducer relay. When the transformer fails, nothing in the system responds: the thermostat goes blank, the furnace won't attempt ignition, and no call for heat or cooling is answered. A failed transformer is often caused by a short in the control wiring, so always inspect low-voltage circuits before installing a replacement.

• Specs: 40VA rating | 120V primary / 24V secondary | Hardwired leads | Factory-matched output for Carrier low-voltage control circuits
• OEM vs Generic: This OEM unit is wound and tested to Carrier's exact 40VA output specification. Generic transformers frequently run undersized VA ratings, causing voltage sag under load that trips the control board or damages the gas valve coil over time.
• Install difficulty: 2/5 — Shut off power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Verify 24V output with a meter after installation and before closing the cabinet. Check all low-voltage wiring for shorts before energizing.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier GB1AAV036045AFJA gas furnace. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering. If your wiring harness shows signs of burning or shorting, replace damaged wiring before installing the new transformer. Our fitment team is available to confirm compatibility before you order.