OEM Carrier 40VA Step-Down Transformer 120V–24V (HT01BC116) for Model PG9MAB036080ABSA

This is the OEM factory-specified control transformer for the Carrier PG9MAB036080ABSA gas furnace. The transformer steps down 120V line voltage to 24V AC, powering the low-voltage control circuit that operates your thermostat, gas valve, inducer, and control board. When this transformer fails, the entire control circuit loses power — symptoms include a completely unresponsive thermostat, no ignition attempt, and a furnace that appears totally dead even though line power is present. Note: OEM part number HT01BC116 has been superseded by HT680054, the current factory-authorized direct replacement shipped in a Carrier-branded box.

• Specs: 40VA rating | 120V primary (input) | 24V secondary (output) | 50/60 Hz single-phase | Foot-mount style | Wire lead connections with insulated female quick-connects
• OEM vs Generic: OEM transformers are wound to exact VA tolerances, protecting downstream components like the control board and gas valve from voltage sag. Generic units often under-deliver VA capacity under load, causing nuisance lockouts or premature board failure.
• Install difficulty: 2/5 — Shut off power at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Photograph all wiring connections before disconnecting. Check for a blown 3A inline fuse on the secondary side as the root cause before replacing the transformer.
• Warranty: 1-year OEM manufacturer warranty. In-stock units ship same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Direct OEM replacement for Carrier model PG9MAB036080ABSA gas furnace. Superseded part HT680054 also replaces HT01BC115, HT01BB126, HT01CT120, HT01BC120, and several other legacy Carrier/Bryant/Payne transformer part numbers. Verify your unit's control circuit voltage requirement (24V) on the data plate before ordering. Our fitment team is available to confirm compatibility — just reach out before you order.