OEM Carrier Transformer 40VA 120V to 24V for Model HC1BNX024000AAAA

This OEM replacement transformer (part number HT01AW229) is the factory-specified step-down transformer for the Carrier HC1BNX024000AAAA system. Its primary function is to convert 120V line voltage down to the 24V signal voltage that powers your thermostat, control board, and all low-voltage control circuitry. When this transformer fails, the entire control circuit loses power — the thermostat goes blank, the system refuses to respond to any call for heating or cooling, and no components energize. It is often the first part to inspect when a system appears completely dead despite the disconnect being on.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | Class 2 transformer | OEM part number HT01AW229 | Factory-matched electrical specifications
• OEM vs Generic: This OEM transformer meets Carrier's exact VA rating and insulation class, preventing nuisance tripping and overheating. Undersized generic transformers — often sold as universal replacements — can overload under normal system demand, leading to repeated failures and potential damage to the control board.
• Install difficulty: 2/5 — Shut off power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire nuts or terminal connectors, multimeter to verify 24V output after installation. Label or photograph all low-voltage wiring before disconnecting from the old transformer.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Orders placed before cutoff ship the same business day from our stocked warehouse.

Compatibility: Engineered specifically for the Carrier HC1BNX024000AAAA. Always verify your unit's data plate and existing transformer VA rating before ordering to confirm fitment. Not sure if this is the right part? Our HVAC parts specialists verify compatibility before you buy — reach out before placing your order and we'll confirm the fit.