OEM Carrier 40VA Control Transformer HT01BC116 for Model PG8UAA042091ADJA

This OEM control transformer is the factory-specified replacement for the Carrier PG8UAA042091ADJA gas furnace. The transformer steps down 120V line voltage to the 24V used by your thermostat, control board, gas valve, and safety circuits. When it fails, the entire low-voltage control system goes dark — your thermostat shows no power, the furnace won't respond to any call for heat or cooling, and you may measure zero voltage at the secondary terminals. Replacing this transformer with the correct OEM unit restores the control circuit to full factory specification.

• Specs: 40VA rating | 120V primary / 24V secondary | Factory-matched impedance and thermal protection | Direct OEM replacement for part number HT01BC116
• OEM vs Generic: This is a genuine Carrier OEM transformer engineered to exact VA rating and impedance tolerances. Generic substitutes may be under-rated for VA load, causing premature thermal cutout trips and repeated control board faults.
• Install difficulty: 2/5 — Shut off power at the breaker and confirm zero voltage with a multimeter before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label and photograph all low-voltage wiring before disconnecting. Re-verify 24V at secondary terminals after installation.
• Warranty: 1-year OEM factory warranty against defects. In stock and ships same business day from our warehouse.

Compatibility: Engineered as a direct fit for Carrier model PG8UAA042091ADJA packaged gas furnace. Confirm 120V/24V and 40VA rating on your unit's data plate before ordering. Our fitment team is available to verify compatibility prior to purchase — no guesswork required.