OEM Carrier Control Transformer 40VA 120V–24V for Model PG8UAA036111ABJA

This OEM control transformer is the factory-specified replacement for the Carrier PG8UAA036111ABJA gas furnace. The transformer is a step-down device that converts 120V line power to the 24V low-voltage signal required to operate the thermostat, gas valve, inducer relay, and all other control-circuit components. When the transformer fails, the entire control circuit goes dead — the thermostat loses power, the furnace will not respond to any call for heat, and nothing happens when the system is energized. A failed transformer is often caused by a short elsewhere in the 24V circuit, so always inspect wiring and components before replacing.

• Specs: 40VA rating | Primary voltage: 120VAC | Secondary voltage: 24VAC | 50/60 Hz single-phase | Replaces OEM part number HT01BC116 (superseded by HT680054)
• OEM vs Generic: This OEM transformer is wound and rated to exact Carrier factory specifications. Generic aftermarket units frequently drift outside rated VA tolerances, causing nuisance trips, control board brownouts, or premature failure of downstream components.
• Install difficulty: 2/5 — Shut off all power at the breaker before servicing. Label and photograph all wire connections before disconnecting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 24V output after install). Check the 3A fuse on the secondary circuit before assuming the transformer itself has failed.
• Warranty: 1-year OEM manufacturer warranty. In-stock units ship same business day when ordered by 5 PM local time.

Compatibility: Designed for the Carrier PG8UAA036111ABJA gas furnace. This transformer also cross-references across a broad family of Carrier, Bryant, and Payne furnace platforms — verify your unit's data plate lists a 120V primary / 24V secondary / 40VA transformer before ordering. If your existing transformer shows 208/240V primary, a different part number is required. Questions about fitment? Our HVAC parts specialists confirm compatibility before your order ships.