OEM Carrier 40VA Control Transformer 120V–24V for Model PG8DAA024070ACJA (HT01BC116 / HT680054)

This OEM step-down control transformer is the factory-specified replacement for the Carrier PG8DAA024070ACJA gas furnace. The transformer converts 120V line voltage down to the 24V AC that powers every low-voltage control circuit in the system — including the thermostat, gas valve, inducer relay, and control board. When it fails, the entire furnace goes silent: no thermostat response, no ignition sequence, and no fan operation. A failed transformer is one of the most common causes of a completely unresponsive furnace.

• Specs: Primary Voltage: 120V AC | Secondary Voltage: 24V AC | VA Rating: 40VA | Frequency: 60 Hz | Phase: Single | Mounting: Foot-mount with wire leads
• OEM vs Generic: This is a genuine Carrier OEM unit (HT680054, the factory-authorized successor to HT01BC116) shipped in a Carrier factory-authorized parts box. Generic transformers often use thinner copper windings and lower-grade core laminations, leading to premature thermal failure — especially on systems with marginal wiring or borderline short circuits.
• Install difficulty: 2/5 — Shut off all power at the breaker before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output post-install). Label all wire connections before disconnecting. Check the 3A low-voltage fuse on the control board — a blown transformer often means a downstream short; replace the fuse and inspect wiring before restoring power.
• Warranty: 1-year OEM manufacturer warranty. In stock and ships same business day from our warehouse when ordered by 5 PM local time.

Compatibility: Direct OEM replacement for Carrier model PG8DAA024070ACJA gas furnace. Part number HT680054 is the current factory-authorized replacement for discontinued OEM part HT01BC116. Also replaces HT01BC115, HT01BB126, HT01CT120, HT01BC120, and several additional legacy Carrier/Bryant part numbers. Verify your unit's data plate voltage (120V primary) before ordering. Our fitment team is available to confirm compatibility before you buy — order with confidence.