OEM Carrier Furnace Control Transformer 120V–24V 40VA for Model PG8MAA024070ABJA

This OEM step-down control transformer is the factory-specified replacement for the Carrier PG8MAA024070ABJA gas furnace. Originally sold under part number HT01BC116, this transformer has been superseded by the current OEM part HT680054 — a direct drop-in replacement shipped in Carrier's factory-authorized packaging. The transformer converts 120V line power down to 24V AC, energizing the thermostat circuit, control board logic, gas valve coil, and all other low-voltage components. When it fails, the entire control circuit goes dark: your thermostat will be unresponsive, the furnace will not ignite, and no fault codes will display on the board — because the board itself has no power.

• Specs: Primary voltage 120V AC | Secondary voltage 24V AC | VA rating: 40VA | Frequency: 60 Hz | Single phase | Foot/chassis mount | Wire lead connections with insulated female quick-connect terminals
• OEM vs Generic: This is a genuine OEM Carrier replacement. Generic transformers frequently use undersized cores and lower-grade winding insulation that can run hot and fail prematurely — or damage downstream low-voltage components by delivering inconsistent output voltage. OEM is the only safe choice when the control board is also at risk.
• Install difficulty: 2/5 — Shut off power at the breaker and verify with a non-contact tester before touching any wiring. Label all wire connections and photograph the original wiring before removal. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (verify 24V output after install). Typical job time: 20–30 minutes.
• Warranty & Shipping: Backed by Carrier's 1-year OEM parts warranty. In stock at NationalHVACParts.com — orders placed before 3 PM local time ship same business day.

Compatibility: Engineered for the Carrier PG8MAA024070ABJA gas furnace. Supersedes OEM part numbers HT01BC116, HT01BC116B, HT01BC115, HT01BB126, HT01CT120, HT01BC120, HT01AW115, and additional legacy Carrier/Bryant/Payne transformer part numbers. Confirm your unit's control voltage is 24V and primary supply is 120V before ordering. Have your model number handy? Our team verifies fitment before you buy — just ask.