OEM Carrier Furnace Control Transformer 120V–24V 40VA — HT01BC116 for Model PG8MAA042090ABJA

This OEM Carrier control transformer is the factory-specified replacement for the Carrier PG8MAA042090ABJA gas furnace. The transformer steps down 120V line voltage to the 24V signal used by your thermostat, control board, gas valve, and all low-voltage accessories. When it fails, the entire control circuit goes dark — the thermostat goes unresponsive, the furnace will not attempt ignition, and no fault codes will display. If you measure 120V at the primary but nothing at the secondary, this is almost certainly your failed component.

• Specs: 120V primary | 24V secondary | 40VA rated | Wire-lead connections | Class 2 step-down transformer | Integrated 3A fuse protection
• OEM vs Generic: The OEM HT01BC116 is wound to exact Carrier factory tolerances, ensuring stable 24V output under full load. Generic alternatives are often undersized in VA rating and may cause nuisance tripping or erratic thermostat behavior.
• Install difficulty: 2/5 — Shut off power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label or photograph all low-voltage wire connections before disconnecting the old transformer. Note: HT01BC116 is superseded by OEM part HT680054 — both are fully compatible.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier PG8MAA042090ABJA gas furnace. This transformer is also used across the Carrier, Bryant, and Payne product families sharing the same 120V/24V/40VA control circuit specification. Always verify primary voltage, secondary voltage, and VA rating on your unit's data plate before ordering. Our parts specialists are available to confirm fitment — just ask before you buy.