OEM Carrier 40VA 120V-24V Control Transformer HT01BC116 for Model PG8JAA036045AAJA

This OEM control transformer is the factory-specified replacement for the Carrier PG8JAA036045AAJA gas furnace. The transformer steps down 120V line voltage to the 24V signal that powers your thermostat, control board, gas valve, and all low-voltage safety circuits. When it fails, nothing works — the furnace will be completely unresponsive, the thermostat will go dark, and no call for heat or cooling will be answered. A failed transformer is often caused by a shorted low-voltage wire or a faulty component drawing excess current, so inspect the 24V circuit before installing a replacement.

• Specs: 40VA rating | 120V primary input | 24V secondary output | Wire-lead connections | Class 2 rated | Replaces OEM part number HT01BC116 (current supersession: HT680054)
• OEM vs Generic: This OEM transformer is wound to exact Carrier factory tolerances, ensuring stable 24V output under full load. Generic transformers may deliver inconsistent voltage, causing nuisance lockouts or intermittent control board faults.
• Install difficulty: 2/5 — Shut off 120V power at the breaker and confirm voltage is dead with a multimeter before touching any wires. Photograph all wire connections before disconnecting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. After installation, check for any downstream short that caused the original failure.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse.

Compatibility: Designed for the Carrier PG8JAA036045AAJA gas furnace. Also cross-references to Bryant and Payne models sharing the same 40VA 120/24V transformer specification. Always verify the VA rating and primary voltage on your existing transformer's label before ordering. Have a fitment question? Our HVAC parts specialists confirm compatibility before you buy.