OEM Carrier Furnace Control Transformer 120V–24V 40VA for Model PG8DAA036050ABJA

This OEM control transformer is the factory-specified replacement for the Carrier PG8DAA036050ABJA gas furnace, originally sold under part number HT01BC116 and updated to the current OEM equivalent HT680054. The transformer is the heartbeat of your furnace's low-voltage control circuit — it steps down 120V line power to the 24V AC signal that drives your thermostat, gas valve, inducer relay, and ignition board. When this part fails, the entire control circuit goes dark: you may see a blank thermostat display, no response to a heat call, or a furnace that simply does nothing when powered on.

• Specs: 120V AC primary input | 24V AC secondary output | 40VA rating | 60 Hz | Foot-mount configuration | Wire lead connections with pre-installed insulated female connectors
• OEM vs Generic: OEM transformers are wound to exact factory VA tolerances, ensuring stable 24V output under full control-circuit load. Undersized or out-of-tolerance generic transformers can cause erratic board behavior, nuisance lockouts, and premature failure of downstream low-voltage components — including your gas valve and IFC board.
• Install difficulty: 2/5 — Shut off power at the breaker and confirm zero voltage with a multimeter before beginning. Photograph all wire connections before removal. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Standard foot-mount bracket aligns to OEM mounting holes for a drop-in swap. Consider adding an in-line 3A fuse on the secondary to protect the new transformer.
• Warranty: 1-year OEM factory warranty. Ships same business day from our stocked warehouse.

Compatibility: Engineered for the Carrier PG8DAA036050ABJA gas furnace. This part also carries cross-reference numbers HT01BC116B, HT01BC115, HT01BB126, HT01CT120, HT01BC120, and 322666-701 — verify your unit's data plate voltage requirements (120V primary / 24V secondary, 40VA) before ordering. Our fitment team is available to confirm compatibility before you buy.