OEM Carrier Transformer 40VA 120V/24V for Model GB3AAV024070ADJA

This OEM replacement transformer (part number HT01BC116) is the factory-specified control circuit transformer for the Carrier GB3AAV024070ADJA gas furnace. The transformer steps down line voltage from 120V to the 24V signal required by your thermostat, control board, gas valve, and all low-voltage safety controls. When this component fails, the entire control circuit goes dark — your thermostat becomes unresponsive, the furnace won't attempt ignition, and nothing happens when you call for heat or cooling. It is one of the first components to test when a unit shows zero response to any thermostat command.

• Specs: 40VA rated | 120V primary / 24V secondary | OEM part number HT01BC116 | Factory-matched output tolerance for reliable low-voltage control
• OEM vs Generic: This is the exact factory-supplied transformer. OEM units are wound and encapsulated to Carrier's thermal and VA specifications. Generic transformers may be under-rated in VA output, causing overheating, nuisance trips, or premature failure under full control circuit load.
• Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter to confirm 24V output after install. Label or photograph all low-voltage wiring before disconnecting from the old unit.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our NationalHVACParts.com warehouse.

Compatibility: Engineered specifically for the Carrier GB3AAV024070ADJA gas furnace. Always verify your existing transformer's VA rating and voltage markings against your unit's data plate before ordering. If you're unsure about fitment, our parts team will confirm compatibility before your order ships — no guesswork required.