OEM Carrier Transformer 40VA 120V to 24V Control Circuit for Model FIOP100311GA

This is the factory OEM replacement transformer (part number HT01BD209) for the Carrier FIOP100311GA. The transformer steps down line voltage from 120V AC to the 24V AC signal required by the low-voltage control circuit — powering the thermostat, control board, contactor coil, and all safety switches. When this transformer fails, the entire control circuit goes dead: the thermostat goes blank, nothing responds to calls for heating or cooling, and the system will not run at all. Replacing this OEM transformer restores factory-spec voltage output and protects downstream components from voltage irregularities common in off-brand substitutes.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Factory-matched output tolerance | Designed for Carrier FIOP100311GA control circuit
• OEM vs Generic: This genuine Carrier OEM transformer (HT01BD209) is wound to exact factory specifications. Generic transformers often output inconsistent 24V, which can cause nuisance lockouts, contactor chatter, and premature control board failure.
• Install difficulty: 2/5 — Shut off all power to the unit before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or terminal connectors. Label and photograph all low-voltage wiring before disconnecting the old transformer.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Engineered specifically for the Carrier FIOP100311GA. Always verify your existing transformer's VA rating and primary/secondary voltages against your unit's data plate before ordering. Our parts specialists are available to confirm fitment — order with confidence and get your system back online fast.