OEM Carrier Furnace Control Transformer 40VA 120V–24V for Model PG9MAB060100ACSA

This OEM control transformer (part number HT01BC116, superseded by HT680054) is the factory-specified step-down transformer for the Carrier PG9MAB060100ACSA gas furnace. It converts 120V line power to the 24V AC signal that energizes your thermostat, gas valve, inducer, and all low-voltage control circuits. When this transformer fails — due to a shorted wiring harness, overloaded control circuit, or age — the result is a completely unresponsive system: the thermostat goes blank, no ignition sequence occurs, and nothing works. Replacing it is one of the most cost-effective furnace repairs available.

• Specs: 40VA capacity | 120V primary / 24V secondary | 50/60 Hz single-phase | Compact 3" L × 2-3/16" W × 2" H form factor | Wire lead connection type
• OEM vs Generic: This OEM-spec transformer is wound to exact factory VA and voltage tolerances. Generic transformers often run outside ±5% tolerance, causing nuisance control-board trips, premature contactor wear, and voided equipment warranties.
• Install difficulty: 2/5 — Always shut off the 120V disconnect and confirm zero voltage with a multimeter before touching any wiring. Tools needed: flathead and Phillips screwdrivers, 1/4" nut driver, multimeter. Photograph all wire connections before disconnecting. Note: a blown transformer is often caused by a downstream short — inspect all low-voltage wiring before powering back on to avoid repeat failure.
• Warranty: 1-year OEM manufacturer warranty. In-stock units ship same business day when ordered by 5 PM local time.

Compatibility: Engineered as the OEM replacement for Carrier model PG9MAB060100ACSA gas furnace. Also cross-references as a direct replacement for legacy part numbers HT01BC115, HT01BB126, HT01CT120, HT01BC120, and several other Carrier/Bryant/Payne transformer part numbers. Verify your unit's control board voltage requirement (24V secondary) and VA load on the data plate before ordering. Need fitment confirmation? Our HVAC parts specialists verify compatibility before you buy — order with confidence.