OEM Carrier 40VA Control Transformer HT01BC116 for Model PG9MAB024040AASA

This OEM control transformer is the factory-specified replacement for the Carrier PG9MAB024040AASA gas furnace. The transformer steps down 120V line voltage to the 24V signal used by the thermostat, control board, gas valve, and every low-voltage component in the system. When this part fails, the entire 24V control circuit goes dark — the thermostat shows no power, the furnace won't respond to any call for heat, and no fault codes can even be displayed. A failed transformer is often misdiagnosed as a control board or thermostat failure, making it the smart first-check for a completely unresponsive furnace.

• Specs: Input 120VAC | Output 24VAC | 40VA rating | OEM part number HT01BC116 | Factory-matched winding insulation class and VA capacity
• OEM vs Generic: This is the genuine OEM Carrier transformer, wound to exact factory VA and voltage tolerances. Generic transformers may run under-rated VA, causing overheating under full 24V load (contactor + gas valve + board + thermostat simultaneously), which trips the internal fuse or burns out the secondary winding prematurely.
• Install difficulty: 2/5 — Power down the furnace at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24VAC output after install). Label all wire connections before removal. The transformer typically mounts to the blower deck or control panel with two screws and uses push-on or screw terminals.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before 3PM local time.

Compatibility: Engineered for Carrier model PG9MAB024040AASA gas furnace. Always verify your unit's data plate and existing transformer VA/voltage ratings before ordering to confirm fitment. Have questions about compatibility? Our HVAC parts specialists verify fitment before you order — no guesswork, no returns.