OEM Carrier 40VA Furnace Control Transformer 120V–24V for Model PG8UAA066111ACJA

This OEM control transformer is the factory-specified replacement for the Carrier PG8UAA066111ACJA gas furnace. The transformer steps down 120V line voltage to 24V AC, powering the entire low-voltage control circuit — including the thermostat, gas valve, inducer relay, and control board. When this transformer fails, every low-voltage component goes dead: the thermostat goes blank, the furnace won't respond to a call for heat, and no error codes appear on the control board. It is often misdiagnosed as a failed board or thermostat. Always verify 24V output at the transformer secondary before replacing more expensive components.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | 60 Hz | Foot-mount configuration | OEM Part# HT01BC116 (superseded by HT680054)
• OEM vs Generic: OEM transformers are wound to exact VA tolerances, protecting downstream components like the gas valve and control board. Generic units frequently run undersized, causing intermittent lockouts and premature board failures under combined load.
• Install difficulty: 2/5 — Disconnect power at the breaker before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter, wire labels. Photograph and label all wire connections before removal. The transformer mounts with two screws; swap wire-for-wire to original terminals.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered by 3 PM local time.

Compatibility: Designed for the Carrier PG8UAA066111ACJA gas furnace. Note that OEM part number HT01BC116 has been superseded by HT680054 — both are 40VA, 120V–24V, and are a direct drop-in fit. Verify primary voltage and VA rating on your unit's data plate before ordering. Need fitment confirmation? Our parts team checks compatibility before you buy.