OEM Carrier 40VA Control Transformer HT01CN241 for Model PF4MNB019000AAAA

This OEM control transformer (part# HT01CN241) is the factory-specified replacement for the Carrier PF4MNB019000AAAA air handler. The transformer steps down 120V line voltage to the 24V AC signal that powers the entire control circuit — including the thermostat, contactor coil, and control board. When this component fails, the result is a completely unresponsive system: the thermostat goes dark, the blower won't run on any mode, and no error codes can be generated because the control voltage is gone entirely.

• Specs: 120V primary input | 24V secondary output | 40VA rated | Designed to factory tolerances for stable, consistent control voltage
• OEM vs Generic: This is the genuine Carrier OEM part (HT01CN241), wound and tested to exact factory specification. Generic transformers often use thinner wire gauges and looser VA tolerances, which can cause erratic thermostat behavior and shortened service life — especially in multi-stage systems.
• Install Difficulty: 2/5 — Always shut off power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (verify 0V before touching terminals). Label or photograph wiring connections before disconnecting. Confirm secondary output reads ~24V AC after installation before closing the panel.
• Warranty: 1-year OEM factory warranty included. In stock and ships same business day from our warehouse.

Compatibility: Direct OEM replacement for Carrier PF4MNB019000AAAA air handler units. Before ordering, verify your existing transformer's primary voltage (120V), secondary voltage (24V), and VA rating on the unit's data plate or existing transformer label. Unsure about fitment? Our HVAC parts specialists confirm compatibility before you order — contact us today.