OEM Carrier Control Transformer 120V–24V 40VA (HT01BC116) for Model PG8MAA024045AAJA

This OEM step-down control transformer is the factory-specified replacement for the Carrier PG8MAA024045AAJA gas furnace. The transformer converts 120V line voltage to 24V AC, powering the low-voltage control circuit that drives the thermostat, gas valve, control board, and all safety switching. When this transformer fails, the entire control circuit goes dead — you'll see a blank thermostat, no system response to a call for heat, or a furnace that won't attempt ignition at all. A shorted transformer may also blow the 3A control fuse repeatedly.

• Specs: Input: 120V AC | Output: 24V AC | Capacity: 40VA | Foot-mount configuration | Wire-lead connections | Factory tolerance-matched for Carrier furnace control boards
• OEM vs Generic: OEM transformers maintain precise 24V output under full VA load, protecting downstream components like the control board and gas valve. Generic units often sag under load, causing erratic thermostat behavior and nuisance lockouts.
• Install difficulty: 2/5 — Disconnect power at the breaker and verify zero voltage before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label all wire leads before disconnecting. Check C and R terminals on the control board for 24V output to confirm successful installation.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Fits Carrier model PG8MAA024045AAJA gas furnaces. OEM part number HT01BC116 has been superseded by the current production part HT680054 — both are covered by this listing. Also cross-references HT01BC115, HT01BB126, HT01CT120, and HT01BC120. Verify input/output voltage and VA rating on your unit's data plate before ordering. Need fitment confirmation? Our team checks compatibility before you buy.