OEM Carrier 40VA Control Transformer 120V–24V for Model PG8MAA066135AAJA (HT01BC116)

This OEM control transformer is the factory-specified replacement for the Carrier PG8MAA066135AAJA gas furnace. It steps down 120V line voltage to 24V AC, powering every low-voltage component in your system — the thermostat, gas valve, inducer relay, and control board. When this transformer fails, absolutely nothing works: the thermostat goes dark, the furnace won't respond to a call for heat, and you may blow a low-voltage fuse repeatedly. Replacing it with the correct OEM unit restores the full 40VA capacity the system was designed for. Note: OEM part number HT01BC116 has been superseded by HT680054 — this listing ships the current factory-authorized replacement.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | 60Hz | Foot-mount configuration | Wire lead connections with pre-installed insulated terminals
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances required by the Carrier control board. Undersized or off-tolerance generic units can cause nuisance fuse trips, erratic thermostat behavior, or premature control board failure.
• Install Difficulty: 2/5 — Turn off power at the breaker and disconnect the furnace service switch before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label or photograph all wire leads before disconnecting. Swap leads one-at-a-time to avoid miswiring.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse — order by 3 PM local time for guaranteed same-day dispatch.

Compatibility: Engineered for Carrier PG8MAA066135AAJA gas furnaces. Also replaces legacy part numbers HT01BC116B, HT01BC115, HT01BB126, HT01CT120, HT01BC120, and HT01AW115 across compatible Carrier, Bryant, and Payne furnace platforms. Always verify input voltage and VA rating on your unit's data plate before ordering. Our fitment team is available to confirm compatibility — contact us before you order.