OEM Carrier Furnace Control Transformer 40VA 120V–24V for Model PG8JAA048135ABJA

This OEM step-down transformer is the factory-specified replacement for the Carrier PG8JAA048135ABJA gas furnace. The control transformer converts 120V line voltage down to the 24V AC signal that powers your thermostat circuit, gas valve, inducer relay, and control board. When it fails, the entire low-voltage control circuit goes dead — the furnace won't respond to the thermostat at all, and no call for heat or cooling will be processed. A failed transformer is often misdiagnosed as a control board failure, making it a smart first diagnostic replacement.

• Specs: 40VA rating | 120V primary | 24V secondary | 60 Hz single-phase | Foot-mount configuration | Wire lead connection type with insulated female quick-connect terminals
• OEM vs Generic: This OEM unit meets Carrier's exact VA rating and insulation class tolerances. Undersized or off-tolerance generic transformers can overheat under combined HVAC/thermostat loads, tripping thermal cutoffs and causing recurring nuisance lockouts.
• Install difficulty: 2/5 — Shut off furnace power at the disconnect before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output post-install). Photograph or label all wire connections before removing the old unit. The swap is straightforward but always confirm no shorted low-voltage wiring before powering back up.
• Warranty: 1-year OEM manufacturer warranty. In-stock — ships same business day from our warehouse when ordered before cutoff.

Compatibility: Direct OEM replacement for Carrier model PG8JAA048135ABJA gas furnace. This part supersedes original part number HT01BC116 and ships as the current production replacement HT680054. Also replaces HT01BC115, HT01BB126, HT01CT120, HT01BC120, and HT01AW115 across multiple Carrier, Bryant, and Payne furnace platforms. Verify your existing transformer's primary voltage (120V), secondary voltage (24V), and VA rating (40VA) on the data plate before ordering. Questions about fitment? Our HVAC parts specialists verify compatibility before you buy.