OEM Carrier 40VA Control Transformer for Model GB3AAV048115ABJA (Part# HT01BC116)

This OEM control transformer is the factory-specified replacement for the Carrier GB3AAV048115ABJA gas furnace. The transformer steps down 120V line voltage to the 24V signal required by your thermostat, control board, gas valve, and all low-voltage control circuit components. When this transformer fails, the entire control circuit loses power — the thermostat goes blank, the system makes no response to heating calls, and no components energize. It is often the first component to inspect when nothing works at all.

• Specs: 40VA rated | 120V primary / 24V secondary | OEM Part# HT01BC116 | Direct factory replacement with matched impedance and thermal protection
• OEM vs Generic: This OEM transformer is wound to Carrier's exact VA rating and thermal cutoff spec. Generic units frequently underperform at peak load, causing nuisance voltage drops that confuse control boards and lead to misdiagnosed faults downstream.
• Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or push-in connectors. Verify 24V output after installation before restoring low-voltage wiring. Photograph all wiring connections prior to removal.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Designed specifically for the Carrier GB3AAV048115ABJA gas furnace. Always verify your existing transformer's VA rating and primary/secondary voltages on the data plate before ordering — substituting an undersized transformer will cause premature failure and may damage control boards. Our fitment team is available to confirm compatibility before you purchase. Order now and ship today.