OEM Carrier 40VA Control Transformer for Model FB4CNF042015ABAA (Part# HT01CN241)

This OEM step-down control transformer is the factory-specified replacement for the Carrier FB4CNF042015ABAA air handler. It converts 120V line voltage to the 24V AC signal that powers your thermostat, control board, and all low-voltage switching circuits. When the transformer fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to any calls for heating or cooling, and no low-voltage components receive power. Replacing this transformer is often the fastest and most affordable fix for a completely unresponsive system.

• Specs: 40VA rated | 120V primary → 24V secondary output | Class 2 low-voltage transformer | Direct OEM replacement, Part# HT01CN241
• OEM vs Generic: This factory OEM unit is wound and insulated to Carrier's exact VA rating and thermal limits. Undersized or off-brand transformers can overheat under multi-zone or accessory loads, causing nuisance trips or premature failure.
• Install difficulty: 2/5 — Shut off power at the breaker and disconnect the low-voltage wiring harness before removal. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter to confirm 24V output after install. Photograph all wiring connections before disconnecting.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier FB4CNF042015ABAA fan coil air handler. Always verify your unit's data plate voltage and VA rating before ordering to confirm fitment. Our parts specialists are available to verify compatibility before you buy — don't guess on a control circuit component. Order today and get same-day shipping.