OEM Carrier Control Transformer 120V–24V 40VA for Model PF4MNB031000ABAA

This is the factory OEM replacement control transformer (part number HT01CN241) for the Carrier PF4MNB031000ABAA air handler. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, and all low-voltage control circuits. When this component fails, the entire control circuit goes dead — your thermostat shows no power, the system won't respond to any call for heating or cooling, and you may blow 24V fuses repeatedly if a secondary short is present.

• Specs: 120V primary | 24V secondary | 40 VA rating | Direct OEM replacement for part number HT01CN241 | Factory-matched to Carrier wiring harness and mounting footprint
• OEM vs Generic: This OEM transformer is wound to exact factory VA and voltage tolerances. Generic transformers often run under-rated VA, causing overheating, nuisance tripping, or premature control board failure — especially under high accessory loads.
• Install difficulty: 2/5 — Shut off all power to the air handler before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Label and photograph all low-voltage wiring before disconnecting from the old transformer.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier PF4MNB031000ABAA air handler. Always verify your unit's data plate voltage and VA requirements match before ordering. Have a question about fitment? Our HVAC parts specialists verify compatibility before you buy — no guesswork.