OEM Carrier 40VA Control Transformer 208/230V–24V for Model PF4MNA042T00AAAA

This OEM Carrier transformer (part number HT01CN241) is the factory-specified 24V control circuit transformer for the Carrier PF4MNA042T00AAAA air handler. The transformer steps down 208/230V line voltage to the 24V AC signal that powers your thermostat, control board, and all low-voltage switching components. When it fails, the entire control circuit goes dark — the thermostat loses power, the system becomes completely unresponsive, and no heating or cooling can be initiated regardless of the call from the stat. A failed transformer is one of the most common root causes of a completely non-responsive HVAC system.

• Specs: 208/230V Primary | 24V Secondary | 40VA rated | Direct OEM drop-in replacement for Carrier PF4MNA042T00AAAA air handlers
• OEM vs Generic: This is a genuine Factory Authorized Carrier part, engineered to exact OEM voltage and VA tolerances. Generic transformers may be rated loosely, causing control board brownouts, nuisance lockouts, or premature failure of downstream low-voltage components.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before proceeding. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Photograph or label all wiring before disconnecting the old transformer.
• Warranty: 1-year OEM manufacturer warranty. In-stock units ship same business day from our warehouse when ordered by 3 PM local time.

Compatibility: Verified OEM fit for Carrier model PF4MNA042T00AAAA air handler. Always confirm your unit's data plate voltage matches 208/230V primary before ordering. Not sure if this is the right part? Our HVAC parts specialists verify fitment before you buy — contact us today and we'll ship it out fast.