OEM Carrier Transformer 40VA 120V–24V for Model HA1BJX036000ADAA

This is the OEM factory replacement transformer (part number HT01AW229) for the Carrier HA1BJX036000ADAA system. The transformer steps down 120V line voltage to the 24V control circuit that powers your thermostat, control board, and all low-voltage switching components. When the transformer fails, the entire control circuit goes dead — the thermostat loses power, the system won't respond to any command, and no heating or cooling operation is possible. A blown transformer is often caused by a shorted wire, a failed component downstream, or a voltage spike, so always inspect the control circuit for shorts before installing a replacement.

• Specs: 40VA rating | 120V primary / 24V secondary | Factory OEM part number HT01AW229 | Engineered to exact Carrier tolerances for reliable low-voltage circuit protection
• OEM vs Generic: OEM transformers are wound and rated to Carrier's exact VA and insulation specs. Generic units may be under-rated in VA, causing premature thermal cutout and repeat failures under normal system load.
• Install difficulty: 2/5 — Shut off power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Test primary and secondary voltages after install to confirm proper output. Note wire colors and terminal labels before disconnecting the old unit.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier HA1BJX036000ADAA system. Verify your existing transformer's VA rating and voltage on the unit's data plate or wiring diagram before ordering. If you're unsure of fitment, our HVAC parts specialists are available to confirm compatibility before you purchase — same-day shipping on all in-stock orders.