OEM Carrier Transformer 40VA 120V to 24V for Model FV4BNF002000AAAA

This OEM replacement transformer (part number HT01CN236) is the factory-specified control circuit transformer for the Carrier FV4BNF002000AAAA fan coil unit. The transformer steps down 120V line voltage to 24V AC, which powers the control board, thermostat, and all low-voltage switching circuits throughout the system. When this component fails, the entire control circuit loses power — resulting in a completely unresponsive thermostat, a blank display, and a system that will not heat, cool, or respond to any input. If your system appears completely dead despite confirmed line voltage at the unit, this transformer is the first component to test.

• Specs: 40VA rating | 120V primary / 24V secondary | Factory-matched output tolerance | OEM part number HT01CN236 | Designed for Carrier fan coil applications
• OEM vs Generic: OEM transformers are wound to exact VA and voltage specifications for the FV4BNF002000AAAA. Undersized or off-spec generic transformers can overheat under normal load, trip thermal cutoffs prematurely, or fail to deliver adequate current to the control board — causing intermittent lockouts or nuisance tripping.
• Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 0V before touching wiring and 24V output after). Photograph all wire connections before removal. The transformer mounts to the control bracket and connects via spade or wire terminals — most technicians complete this swap in under 20 minutes.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Orders placed before cutoff ship same business day from our climate-controlled warehouse.

Compatibility: This listing is for Carrier model FV4BNF002000AAAA fan coil units using OEM part number HT01CN236. Always verify your existing transformer's VA rating and primary/secondary voltage from the data plate or wiring diagram before ordering to confirm fitment. Our parts specialists are available to verify compatibility before you purchase — no guesswork required. In stock and ships today.