OEM Carrier 40VA Control Transformer for Model FB4ANF048010AFAA

This is the factory-original OEM replacement transformer (part number HT01CN236) for the Carrier FB4ANF048010AFAA fan coil air handler. The control transformer steps down 120V line voltage to 24V to power the low-voltage control circuit — including the thermostat, contactor coil, and control board. When this transformer fails, the entire control circuit goes dark: the thermostat loses power, the system stops responding to calls for cooling or heating, and nothing works. A failed transformer is often misdiagnosed as a thermostat or control board issue, so always test transformer output voltage first.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01CN236 | Direct factory replacement with matched impedance and thermal protection
• OEM vs Generic: OEM transformers are wound to exact VA and voltage specifications for the Carrier control circuit. Undersized or off-tolerance generic units can overheat, trip thermal protection repeatedly, or damage the control board by delivering unstable voltage.
• Install Difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or quick-connects. Label or photograph all low-voltage wiring before disconnecting. Confirm 120V input and 24V output with a multimeter after installation before closing the unit.
• Warranty: 1-year OEM factory warranty against defects. Orders placed before cutoff ship same business day from our stocked warehouse.

Compatibility: Designed specifically for the Carrier FB4ANF048010AFAA fan coil air handler. Verify the transformer VA rating and primary/secondary voltages on your unit's data plate before ordering. If you're unsure of fitment, our HVAC parts specialists can confirm compatibility before you buy — same-day shipping available on all in-stock orders.