OEM Carrier Transformer 40VA 120V/24V for Model FIOP100B301GA

This is the factory OEM replacement transformer (part number HT01BD209) for the Carrier FIOP100B301GA. The transformer steps down line voltage (120V) to the 24V signal required to power the control board, thermostat, and all low-voltage control circuits throughout the system. When this component fails, nothing responds — the thermostat goes dark, the system ignores all calls for heating or cooling, and you may find a blown fuse on the control board. Replacing this transformer is one of the most cost-effective fixes for a completely unresponsive HVAC system.

• Specs: 40VA rating | 120V primary input | 24V secondary output | OEM part number HT01BD209 | Factory-matched electrical tolerances for reliable low-voltage control circuit performance
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage specifications. Generic transformers may underperform at rated VA load, causing nuisance tripping, voltage sag to the control board, or premature fuse failure — especially in multi-stage or accessory-heavy systems.
• Install Difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label or photograph all low-voltage wiring connections before removal. Verify 24V output with a multimeter after installation before restoring line voltage.
• Warranty: 1-year OEM factory warranty against defects. Orders placed before cutoff ship the same business day from our stocked warehouse.

Compatibility: Designed as the direct OEM replacement for the Carrier FIOP100B301GA. Always verify your existing transformer's VA rating, primary voltage, and secondary voltage against your unit's data plate before ordering. Our team is available to confirm fitment — reach out before you buy if you have any questions.