OEM Carrier Control Transformer 40VA for Model C48A203061

This OEM replacement transformer (part number HT01BD236) is the factory-specified step-down transformer for the Carrier C48A203061 packaged unit. The transformer converts 120V line voltage to the 24V AC signal that powers your thermostat, control board, contactor coil, and all low-voltage control circuitry. When this component fails, the entire control system goes dark — the thermostat becomes unresponsive, the unit won't call for heating or cooling, and no low-voltage components will operate. It is often the first component to check when nothing works at all.

• Specs: 40VA rated | 120V primary / 24V secondary | Class 2 transformer | Designed to OEM factory tolerances for reliable, stable low-voltage output
• OEM vs Generic: This is a genuine OEM Carrier part (HT01BD236), ensuring exact VA capacity and terminal compatibility. Generic transformers may underperform under full low-voltage load, causing erratic control board behavior or premature failure.
• Install Difficulty: 2/5 — Disconnect power at the breaker and verify voltage is absent before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Label all wires before disconnecting. Always verify output voltage (24V AC) after installation before closing the unit.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C48A203061 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltage on the unit's data plate or wiring diagram before ordering. If you're unsure of fitment, our HVAC parts team can verify compatibility before you purchase — same-day shipping available on all in-stock orders.