OEM Carrier Furnace Control Transformer 40VA 120V/24V for Model PG8MAA066110ADJA

This OEM control transformer is the factory-specified replacement for the Carrier PG8MAA066110ADJA gas furnace. The transformer steps down 120V line voltage to 24V to power the furnace's entire low-voltage control circuit — including the thermostat, gas valve, inducer relay, and control board. When it fails, nothing in the system responds: no ignition attempt, no blower, no error codes. A failed transformer is often mistaken for a bad control board, making it the smart first diagnostic step.

• Specs: OEM Part# HT01BC116 (superseded by HT680054) | Primary: 120 VAC | Secondary: 24 VAC | VA Rating: 40VA | Frequency: 50/60 Hz | Single Phase | Wire lead connections
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Undersized or off-tolerance generic transformers can overheat, blow the low-voltage fuse repeatedly, or cause erratic control board behavior — costing far more than the part itself.
• Install Difficulty: 2/5 — Shut off power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Photograph all wiring before disconnecting. The transformer typically mounts inside the blower compartment with two screws.
• Warranty: 1-year OEM manufacturer warranty. In-stock units ship same business day from our warehouse when ordered before cutoff.

Compatibility: Direct OEM replacement for Carrier model PG8MAA066110ADJA gas furnace. Also supersedes legacy part numbers HT01BC115, HT01BB126, HT01CT120, HT01BC120, HT01AW115, and HT01AA012 across compatible Carrier, Bryant, and Payne furnace platforms. Verify your unit's data plate voltage rating before ordering. Need fitment confirmation? Our HVAC parts specialists verify compatibility before you buy — order with confidence and get your heat back today.