OEM Carrier Transformer 40VA 120V/24V for Model GB3AAV036055AAJA

This OEM control circuit transformer (part number HT01BC116) is the factory-specified replacement for the Carrier GB3AAV036055AAJA gas furnace. The transformer steps down 120V line voltage to 24V AC to power the low-voltage control circuit — including the thermostat, control board, gas valve, and safety switches. When it fails, the entire control circuit goes dead: the thermostat shows no response, the furnace won't initiate a call for heat, and nothing happens when you adjust the setpoint. A blown transformer is often caused by a wiring short downstream, so always inspect low-voltage wiring before replacing.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Class 2 transformer | Direct OEM replacement for part number HT01BC116
• OEM vs Generic: This factory OEM unit is wound to exact VA and voltage tolerances for the GB3AAV036055AAJA. Generic transformers may underperform under peak load, causing nuisance lockouts or premature control board failure due to voltage sag.
• Install difficulty: 2/5 — Shut off power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdriver, needle-nose pliers, multimeter. Verify secondary output is 24–28V AC after installation before restoring full power. Check low-voltage wiring for shorts first.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse.

Compatibility: Designed for the Carrier GB3AAV036055AAJA gas furnace. Confirm your existing transformer's VA rating and primary/secondary voltages on the unit's data plate before ordering. If your transformer has a visible burn mark or internal short, inspect the 24V circuit for wiring faults before installing the new part. Our team is available to verify fitment — order with confidence and get back to comfort fast.