OEM Carrier Control Transformer 120V-24V 40VA — HT01BC116 for Model PG8JAA066135ADJA

This OEM step-down control transformer (part number HT01BC116, superseded by HT680054) is the factory-specified replacement for the Carrier PG8JAA066135ADJA gas furnace.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, control board, and inducer relay. When this transformer fails, the entire control circuit goes dead: the thermostat loses power, the furnace won't respond to any call for heat, and you'll measure 0V between the R and C terminals on the control board.

• Specs: Input: 120V AC | Output: 24V AC | VA Rating: 40VA | Connection: Wire Leads | Mounting: Foot Mount | Includes integrated 3A fuse protection
• OEM vs Generic: OEM transformers are wound and tested to exact Carrier factory tolerances, ensuring stable 24V output under full load. Generic units can sag under load, causing erratic thermostat behavior, nuisance lockouts, and premature control board failure.
• Install difficulty: 2/5 — Shut off the furnace disconnect and confirm 0V at line-voltage terminals before touching any wiring. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper. Photograph all wiring connections before disconnecting. Verify 24V output at R–C terminals after installation.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Fits Carrier model PG8JAA066135ADJA gas furnace. Note: HT01BC116 has been superseded — this listing ships the current OEM replacement HT680054, a direct drop-in that replaces HT01BC116, HT01BC115, HT01BB126, HT01BC120, and related part numbers. Verify your unit's control circuit voltage before ordering. Our fitment team is available to confirm compatibility before you buy.