OEM Carrier 40VA Control Transformer for Model FA4ANC042008AGAA Air Handler

This OEM replacement transformer (part# HT01CN236) is the factory-specified 40VA step-down transformer for the Carrier FA4ANC042008AGAA fan coil air handler. Its job is to convert 120V line voltage into the 24V AC signal that powers your thermostat, control board, and all low-voltage switching components. When this transformer fails, the entire control circuit goes dark — your thermostat display goes blank, the system won't respond to calls for heating or cooling, and you may find a blown fuse on the control board from a secondary short.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Hardwired lead connections | Factory-matched impedance and thermal protection for the FA4ANC042008AGAA platform
• OEM vs Generic: The OEM HT01CN236 transformer is wound and rated to exact Carrier factory specifications. Generic transformers often use lower-grade core laminations that run hotter and fail prematurely, risking repeated control board fuse failures and nuisance lockouts.
• Install difficulty: 2/5 — Always shut off power at the breaker and confirm voltage is zero before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Label or photograph existing wire connections before disconnecting. Replace the control board fuse at the same time to clear any secondary short damage.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Engineered for the Carrier FA4ANC042008AGAA fan coil air handler. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering. If you're unsure of fitment, our parts specialists verify compatibility before you commit to a purchase — same-day shipping on all in-stock orders.