OEM Carrier 40VA Control Transformer 208/230V–24V for Model PF4MNB037L00ACAA

This OEM Carrier transformer (part #HT01CN241) is the factory-specified 40VA step-down transformer for the Carrier PF4MNB037L00ACAA air handler. Its job is critical: it steps line voltage (208/230V primary) down to the 24V signal voltage that powers your thermostat, control board, and all low-voltage safety circuits. When this transformer fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to any call for heating or cooling, and no fault codes will display. It is often the first component to check when a system has completely lost communication.

• Specs: 208/230V Primary | 24V Secondary | 40VA Power Rating | Direct OEM replacement for Carrier part #HT01CN241
• OEM vs Generic: This is a genuine OEM Carrier transformer wound to exact factory VA and voltage tolerances. Generic transformers can exhibit voltage sag under load, leading to nuisance lockouts, erratic thermostat behavior, and premature control board failure.
• Install Difficulty: 2/5 — Shut off power at the breaker before any work. Tools needed: flathead and Phillips screwdrivers, wire nuts or terminal connectors, multimeter to verify 24V output after install. Label all wires before disconnecting. Most techs complete this swap in under 30 minutes.
• Warranty: 1-year OEM manufacturer warranty. In stock and ships same business day from our warehouse.

Compatibility: Verified for use in Carrier model PF4MNB037L00ACAA air handlers. Always confirm your existing transformer's primary voltage, secondary voltage, and VA rating against your unit's data plate before ordering. Have a question about fitment? Our HVAC parts specialists confirm compatibility before you buy — reach out today and we'll get you the right part, fast.