OEM Carrier 40VA Control Transformer 120V–24V for Model PG8JAA036070AAJA (Replaces HT01BC116)

This OEM 40VA step-down transformer is the factory-specified replacement for the Carrier PG8JAA036070AAJA gas furnace. It converts 120V line voltage to the 24V signal required to power the control board, thermostat circuit, and all low-voltage system controls. When this transformer fails, your thermostat goes dark, your furnace won't respond to a call for heat, and the entire control circuit goes dead — symptoms often mistaken for a failed thermostat or control board.

• Specs: 40VA | Primary: 120VAC | Secondary: 24VAC | 50/60 Hz | Single-phase | Compact chassis-mount design | OEM Part: HT01BC116 (superseded by HT680054)
• OEM vs Generic: This is a genuine OEM-specification transformer built to factory tolerance. Generic transformers often run under-rated VA capacities, causing nuisance tripping, premature failure, and potential control board damage under peak load.
• Install Difficulty: 2/5 — Turn off all power to the furnace at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label all wiring leads before disconnecting the old transformer. Verify 24VAC output with a multimeter after installation before restoring full power.
• Warranty: 1-year OEM manufacturer warranty. In-stock units ship same business day from our warehouse when ordered by 3PM local time.

Compatibility: Designed for the Carrier PG8JAA036070AAJA gas furnace. This part directly replaces OEM part number HT01BC116 and its current OEM successor HT680054. Also cross-references HT01BC115, HT01BB126, HT01CT120, HT01BC120, HT01AW115, HT01AA012, HT01AQ110, HT01CT210, and HT01CT20006. Always confirm your existing transformer's voltage and VA rating on the unit data plate before ordering. Not sure it fits? Contact our parts team — we verify fitment before you buy.