OEM Carrier 40VA Control Transformer HT01BD236 for Model C48A303061

This is the factory OEM replacement transformer (part number HT01BD236) for the Carrier C48A303061 packaged unit. The transformer steps down 120V line voltage to the 24V signal required by the control board, thermostat, contactor coil, and all low-voltage components. When this part fails, the entire control circuit goes dead — the thermostat shows no response, the system won't call for heating or cooling, and no components energize. A failed transformer is often misdiagnosed as a bad thermostat or control board, making correct diagnosis essential before replacing costlier parts.

• Specs: 40VA rating | 120V primary / 24V secondary | Class 2 low-voltage output | Factory-matched OEM dimensions and terminal configuration for direct drop-in installation
• OEM vs Generic: The OEM HT01BD236 transformer is wound to Carrier's exact VA rating and insulation class. Generic transformers frequently use undersized windings that overheat under full control-circuit load, causing nuisance trips and premature failure of downstream components.
• Install difficulty: 2/5 — Disconnect power at the breaker and verify zero voltage with a multimeter before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Label all low-voltage wires before disconnecting. Confirm primary fuse or circuit protection after installation.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our NationalHVACParts.com warehouse.

Compatibility: Designed specifically for the Carrier C48A303061 packaged unit. Verify your unit's data plate shows 120V primary control voltage and 24V secondary before ordering. If your system runs a 208/240V primary transformer, do not substitute — contact our fitment team for the correct part. Order today and get same-day shipping on all in-stock OEM Carrier parts.