OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
This OEM replacement transformer (part# HT01AW229) is the factory-specified 40VA step-down transformer for the Carrier HA1AJX036000ABAA split-system unit. The transformer converts 120V line voltage down to the 24V AC signal that powers your thermostat, control board, contactor coil, and all low-voltage safety circuits. When this component fails, the entire control circuit goes dark — your thermostat will appear dead, the system will not respond to any call for heating or cooling, and no low-voltage components will operate. It is often the first part to check when nothing in the system seems to respond.
Compatibility: Engineered specifically for the Carrier HA1AJX036000ABAA (3-ton split-system, R-410A). Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering. Our parts specialists are available to confirm fitment — reach out before you buy for complete peace of mind. In stock and ready to ship today.