OEM Carrier Transformer 40VA 120V–24V for Model HA1CJX048000ABAA

This OEM step-down transformer (part number HT01AW229) is the factory-specified replacement for the Carrier HA1CJX048000ABAA packaged unit. The transformer converts 120V line voltage to the 24V AC signal that powers your thermostat, control board, contactor coil, and all low-voltage control functions. When it fails, nothing in the system responds — the thermostat goes blank, the unit won't call for heating or cooling, and the control board loses all power. It is often the first component to inspect when the entire control circuit goes dark.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Factory-matched OEM part number HT01AW229 | Compact foot-mount or DIN-rail compatible design
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances required by the Carrier control board. Undersized or off-tolerance generic units can drop voltage under load, causing nuisance lockouts, erratic board behavior, or premature contactor coil failure.
• Install difficulty: 2/5 — Disconnect power at the disconnect box and verify zero voltage before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm 24V output after install). Label all low-voltage wires before disconnecting from the secondary terminals.
• Warranty: 1-year OEM factory warranty against defects. In-stock units ship same business day when ordered before 3 PM local time.

Compatibility: Designed for the Carrier HA1CJX048000ABAA 4-ton packaged unit. Always confirm primary voltage (120V) and VA rating on your unit's data plate before ordering. If your unit runs 208/240V primary, do not order this part — contact our team for the correct transformer. Our HVAC parts specialists are available to verify fitment before you place your order.