OEM Carrier Transformer 40VA 120V/24V for Model FPAA075D13CN (HT01BC116)

This OEM replacement transformer (part number HT01BC116) is the factory-specified control circuit transformer for the Carrier FPAA075D13CN packaged unit. The transformer steps down 120V line voltage to the 24V signal voltage required by your thermostat, contactor coil, control board, and all low-voltage safety circuits. When it fails, the entire control circuit goes dead — your thermostat displays nothing, the system ignores all calls for heating or cooling, and no safety faults can even be logged. If your system is completely unresponsive and you've confirmed 120V supply voltage at the unit, a failed transformer is one of the first components to test.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01BC116 | Factory-matched to Carrier FPAA075D13CN wiring harness and mounting bracket
• OEM vs Generic: This OEM transformer is wound and insulated to Carrier's exact VA rating and thermal class, ensuring it won't overheat under sustained control circuit load. Generic transformers often underrate VA capacity, causing premature burnout — especially when multiple zone valves or relay coils are on the 24V circuit simultaneously.
• Install difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 0V before touching wiring). Label or photograph all 24V low-voltage wiring connections before removal. Secondary wires are color-coded but positions vary by wiring age.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Orders placed before cutoff ship the same business day from our climate-controlled parts warehouse.

Compatibility: Designed for the Carrier FPAA075D13CN packaged unit. Confirm your existing transformer's VA rating and primary/secondary voltages on the data plate before ordering. If your unit shares a 24V circuit with additional accessories (humidifiers, zone boards, UV lights), verify total VA draw does not exceed transformer capacity. Our parts specialists are available to confirm fitment before you purchase — no guesswork.