OEM Carrier Control Transformer 40VA for Model FIOP200B511GA — Part HT01BD209

This is the factory OEM replacement transformer (part number HT01BD209) for the Carrier FIOP200B511GA unit. The transformer steps down line voltage (120V) to the 24V AC control voltage that powers your thermostat, contactor coil, and control board logic. When this component fails, the entire control circuit goes dark — the thermostat becomes unresponsive, the system won't call for heating or cooling, and no safety outputs will activate. It is one of the first components to test when a system shows zero control response.

• Specs: 40VA rating | 120V primary input | 24V secondary output | Factory OEM tolerance | Designed for Carrier FIOP200B511GA control circuit requirements
• OEM vs Generic: This is a genuine Carrier OEM part, manufactured to exact VA and voltage specifications. Generic transformers often underperform under peak load, causing intermittent control failures and premature contactor coil burnout — OEM is always the recommended choice for reliable, long-term operation.
• Install difficulty: 2/5 — Shut off all power to the unit at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper, and needle-nose pliers. Test secondary output with a multimeter (should read 24–28V AC) before powering up. Photograph all wiring connections prior to removal.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Ships same business day from our stocked warehouse.

Compatibility: Designed as a direct OEM replacement for the Carrier FIOP200B511GA. Always verify your unit's control board input requirements and existing transformer VA rating on the data plate or wiring diagram before ordering. If you're unsure of fitment, our HVAC parts specialists can verify compatibility before you purchase — same-day shipping available on all in-stock orders.