OEM Carrier 40VA Control Transformer 208/230V–24V for Model PF4MNB031000AAAA

This is the factory OEM replacement transformer (part number HT01CN241) for the Carrier PF4MNB031000AAAA fan coil and air handler unit. The control transformer steps down the 208/230V line voltage to a safe 24V signal used to power the thermostat circuit, control board, and all low-voltage switching components. When this transformer fails, the entire control circuit goes dead — the thermostat display may go blank, the system will not respond to calls for heating or cooling, and no safety lockouts will function. Replacing a failed transformer is one of the most cost-effective repairs in HVAC service.

• Specs: 40VA rated | 208/230V primary input | 24V secondary output | 50/60Hz | Direct OEM drop-in replacement for Carrier PF4MNB031000AAAA
• OEM vs Generic: This OEM unit is manufactured to exact Carrier factory specifications, ensuring correct VA capacity and winding insulation class. Undersized or off-spec generic transformers can overheat, blow the control fuse repeatedly, or fail prematurely under full 24V load.
• Install difficulty: 2/5 — Disconnect all power before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Confirm secondary output voltage (24V AC) with a meter before powering the full system. Photograph all wiring connections before removal.
• Warranty: 1-year OEM manufacturer warranty. In-stock units ship same business day when ordered by 3 PM local time.

Compatibility: Engineered for the Carrier model PF4MNB031000AAAA fan coil/air handler. Always verify the 208/230V primary and 24V secondary 40VA rating against your unit's data plate before ordering. Need help confirming fitment? Our HVAC parts specialists are standing by — contact us before you order.