OEM Carrier Transformer 208/230V Primary 24V Secondary 40VA for Model PF4MNB025000AAAA

This is the genuine OEM replacement transformer (part #HT01CN241) factory-specified for the Carrier PF4MNB025000AAAA fan coil and air handler. The transformer steps down line voltage (208/230V primary) to 24V AC on the secondary, powering the entire 24V control circuit — including the thermostat, contactor coil, and control board. When this transformer fails, you'll typically see a completely dead control system: the thermostat goes blank, the system won't respond to any command, or a fuse blows repeatedly on the secondary side. A failed transformer is often misdiagnosed as a bad thermostat or control board — always test transformer output voltage first before replacing more expensive components.

• Specs: 208/230V Primary | 24V Secondary | 40VA Rating | Direct OEM drop-in replacement | Part #HT01CN241
• OEM vs Generic: OEM transformers are wound to exact VA and voltage-regulation tolerances. Undersized or off-tolerance aftermarket units can cause nuisance fuse trips, erratic thermostat behavior, and premature control board failure — the OEM unit eliminates that risk entirely.
• Install Difficulty: 2/5 — Always shut off the disconnect and verify zero voltage with a meter before touching any wiring. Label all wire connections before removal. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Most techs complete the swap in under 20 minutes.
• Warranty: 1-year OEM manufacturer warranty. In-stock units ship same business day from our warehouse when ordered by 5PM local time.

Compatibility: Factory-specified for the Carrier PF4MNB025000AAAA fan coil/air handler. Always verify your unit's wiring diagram and confirm 208/230V primary voltage at the transformer location before ordering. Need help confirming fitment? Our HVAC parts specialists are standing by — order with confidence and get your system back up fast.