OEM Carrier 40VA Control Transformer 120V–24V for Model PG8JAA066110AAJA

This OEM control transformer is the factory-specified replacement for the Carrier PG8JAA066110AAJA gas furnace. The transformer steps down 120V AC line voltage to 24V AC, powering the furnace's entire low-voltage control circuit — including the thermostat, gas valve, inducer relay, and control board. When the transformer fails, the result is total loss of control: a blank thermostat display, no ignition attempt, and a furnace that appears completely dead. A blown internal fuse or shorted low-voltage wiring are the most common causes of transformer failure.

• Specs: 40VA rating | 120V AC primary input | 24V AC secondary output | 60 Hz | Foot-mount configuration | OEM part number HT01BC116 (superseded by HT680054)
• OEM vs Generic: This OEM unit is manufactured to exact Carrier factory tolerances and includes proper foot-mount geometry for a clean, no-modification installation. Generic transformers frequently have mounting mismatches and inconsistent VA ratings that can damage sensitive control boards.
• Install difficulty: 2/5 — Always disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter (to confirm 24V output before re-energizing). Photograph all wiring connections prior to removal. Check low-voltage wiring for shorts before installing — a shorted wire will blow the new transformer immediately.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse.

Compatibility: Engineered as a direct OEM replacement for the Carrier PG8JAA066110AAJA gas furnace. Cross-references include HT01BC116, HT01BC116B, HT01BC115, HT680054, and HT01BC120. Verify your unit's control circuit voltage (24V) and VA demand on the rating plate before ordering. Need fitment confirmation? Our HVAC parts specialists verify compatibility before you buy — order now and ship today.