OEM Carrier Furnace Control Transformer 40VA 120V–24V for Model PG9MAB060140AASA

This OEM step-down transformer is the factory-specified replacement for the Carrier PG9MAB060140AASA gas furnace, sold under OEM part number HT01BC116 (superseded by HT680054). The transformer converts 120V line voltage down to 24V AC to power all low-voltage control components — including the thermostat, gas valve, inducer relay, and integrated furnace control board. When this part fails, the entire low-voltage control circuit goes dead: the thermostat display may go blank, the furnace will not respond to a call for heat, and no diagnostic fault codes will appear because the board itself has no power to operate.

• Specs: 40VA rating | 120V primary (input) | 24V secondary (output) | 60 Hz single-phase | Wire lead connections with insulated female quick-connects | Dimensions: 3″ L × 2-3/16″ W × 2″ H
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Undersized or off-tolerance generic transformers can overheat under the combined load of a thermostat, gas valve, and control board — leading to repeated nuisance failures and potential low-voltage wiring damage.
• Install difficulty: 2/5 — Always shut off power at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (verify 24V output after install). Photograph all wire connections before disconnecting. Check 24V between the R and C terminals on the control board to confirm correct operation after replacement.
• Warranty: 1-year OEM manufacturer warranty. In-stock units ship same business day from our warehouse when ordered by 5 PM local time.

Compatibility: Fits Carrier model PG9MAB060140AASA gas furnace. Also replaces legacy part numbers HT01BC115, HT01BB126, HT01CT120, HT01BC120, HT01AW115, HT01AA012, HT01AQ110, HT01CT210, and 322666-701. Verify your unit's data plate and existing transformer wire lead configuration before ordering. Need fitment confirmation? Our HVAC parts specialists are available to verify compatibility before you buy — order with confidence.