OEM Carrier Transformer 40VA 120V to 24V for Model PF4MNB043T00AAAA

This OEM replacement transformer (part number HT01CN241) is the factory-specified control circuit transformer for the Carrier PF4MNB043T00AAAA air handler. Its sole but critical job is to step line voltage (120V) down to 24V to power the low-voltage control circuit — including your thermostat, zone controls, and every relay on the board. When this transformer fails, nothing works: the thermostat goes dark, the system is completely unresponsive, and you may measure zero volts on the secondary side with a multimeter.

• Specs: Input: 120V AC | Output: 24V AC | Rating: 40VA | OEM Part Number: HT01CN241 | Factory-matched insulation class and thermal protection
• OEM vs Generic: This is the genuine Carrier OEM unit — built to exact VA and thermal cutout specifications. Generic transformers often run undersized VA ratings, causing premature burnout under normal load from thermostats and zone boards.
• Install Difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Photograph and label all wiring connections before disconnecting the old unit. Verify 24V output on secondary terminals before closing the panel.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Designed and tested for the Carrier PF4MNB043T00AAAA air handler. Always confirm input voltage and VA rating on your unit's data plate before ordering — mismatched VA ratings will cause repeated transformer failure. Our fitment team is available to verify compatibility before you purchase.