OEM Carrier Transformer 40VA 120V to 24V for Model CH13NA03700GACBA

This OEM replacement transformer (part number HT01AW229) is the factory-specified control circuit transformer for the Carrier CH13NA03700GACBA split-system air conditioner. The transformer steps down line voltage from 120V to 24V to power the low-voltage control circuit — including your thermostat, contactor coil, and control board. When this transformer fails, the entire control circuit goes dead: the thermostat displays nothing, the system won't respond to calls for cooling, and no safety or operating functions will execute. It is often the first component to check when nothing works at all.

• Specs: 40VA rated | 120V primary input | 24V secondary output | Single-phase | Factory-matched OEM part number HT01AW229
• OEM vs Generic: This OEM transformer is wound to exact VA and voltage specifications for the CH13NA03700GACBA control board. Generic transformers may be under-rated in VA, causing them to overheat and fail prematurely under normal system load — especially with added accessories like humidistats or zone controllers.
• Install difficulty: 2/5 — Disconnect power at the breaker and verify with a non-contact voltage tester before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Label or photograph all low-voltage wiring before disconnecting. Reconnect to matching primary and secondary terminals and restore power to verify 24V output.
• Warranty: 1-year OEM factory warranty. Leaves our warehouse the same business day when ordered before 3 PM.

Compatibility: Designed for Carrier model CH13NA03700GACBA split-system condensers. Confirm your existing transformer's VA rating and input/output voltages on the unit data plate or wiring diagram before ordering. Need help verifying fitment? Our HVAC parts specialists confirm compatibility before your order ships.