OEM Carrier Transformer 40VA 120V to 24V for Model FV4BNB003000AAAA

This OEM replacement transformer (part number HT01CN236) is the factory-specified control circuit transformer for the Carrier FV4BNB003000AAAA fan coil air handler. The transformer steps down 120V line voltage to the 24V AC signal that powers the thermostat, control board, and all low-voltage components. When this part fails, the entire control circuit goes dead — your thermostat will appear blank or unresponsive, and the system will not heat, cool, or respond to any commands. A blown fuse on the secondary side of the transformer is often the first sign of failure.

• Specs: Input: 120V AC | Output: 24V AC | VA Rating: 40VA | OEM Part Number: HT01CN236 | Factory-matched to Carrier FV4BNB003000AAAA air handler specifications
• OEM vs Generic: This OEM transformer meets exact VA rating and insulation class requirements. Undersized or off-brand transformers can overheat under full control-circuit load, tripping thermal protection and causing intermittent lockouts or premature failure.
• Install difficulty: 2/5 — Power down and lock out the unit at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Always verify 0V at terminals before handling wiring. Label all low-voltage wires before disconnecting to ensure correct reassembly.
• Warranty: 1-year OEM factory warranty against defects. In-stock units ship same business day from our warehouse when ordered before the daily cutoff.

Compatibility: Designed specifically for the Carrier FV4BNB003000AAAA fan coil air handler. Confirm your existing transformer's input voltage, output voltage, and VA rating on the unit data plate or old transformer label before ordering. If your control circuit fuse is blowing repeatedly, inspect low-voltage wiring for shorts before installing a new transformer. Our HVAC parts specialists are available to verify fitment — order with confidence and get back to comfort fast.