OEM Carrier Control Transformer 120V–24V 40VA for Model PG9MAB048100AASA (HT01BC116 / HT680054)

This OEM step-down control transformer is the factory-specified replacement for the Carrier PG9MAB048100AASA gas furnace. The transformer converts 120V line voltage down to 24V AC to power all low-voltage control circuit components — including the thermostat, gas valve, inducer relay, and IFC control board. When this transformer fails, the entire control circuit goes dead: the thermostat shows no response, the furnace will not initiate a heating cycle, and nothing happens when the system calls for heat. Note: OEM part number HT01BC116 has been superseded by HT680054, the current factory-authorized direct replacement.

• Specs: Primary Voltage: 120V AC | Secondary Voltage: 24V AC | VA Rating: 40VA | Frequency: 60 Hz | Single Phase | Foot-mount configuration with wire lead connections
• OEM vs Generic: This OEM transformer is wound to exact factory VA tolerances. Undersized or off-tolerance generic transformers overheat under full low-voltage load, tripping thermal cutoffs and causing intermittent lockouts — a common callback nightmare for technicians.
• Install Difficulty: 2/5 — Shut off power at the breaker and disconnect the furnace before touching any wiring. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (verify 0V before handling). Photograph all wire connections before removal. Match wire leads carefully: primary (120V) and secondary (24V) sides are both present.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Direct OEM replacement for Carrier model PG9MAB048100AASA gas furnaces. Supersedes legacy part number HT01BC116; current shipping part is HT680054. Also replaces HT01BC115, HT01BB126, HT01CT120, HT01BC120, and several other Carrier/Bryant/Payne cross-references. Verify your unit's data plate voltage requirements before ordering. Our fitment team is available to confirm compatibility — just reach out before you buy.