OEM Carrier Control Transformer 40VA 120V/24V for Model C48A805064

This OEM Carrier transformer (part number HT01BD702) is the factory-specified replacement for the C48A805064 packaged unit. The transformer steps line voltage (120V) down to 24V to power the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When it fails, nothing works: the thermostat goes blank, the system won't respond to calls for heating or cooling, and you may measure zero voltage at the secondary terminals. A failed transformer is often caused by a short in the control wiring or a stuck contactor coil drawing excess current, so always inspect the downstream circuit before installing a replacement.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | Mounts via standard foot or stud bracket | OEM part number HT01BD702
• OEM vs Generic: This OEM transformer is wound to Carrier's exact VA rating and insulation class, ensuring reliable 24V output under full control-circuit load. Generic transformers may be under-rated for VA draw, leading to thermal cutout trips and premature failure.
• Install difficulty: 2/5 — Disconnect power at the disconnect box and confirm zero voltage with a multimeter before handling. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Label all wiring before removal. Test secondary output voltage after installation before closing the cabinet.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C48A805064 packaged unit. Verify your existing transformer's primary/secondary voltage and VA rating on the unit's data plate or wiring diagram before ordering. Need fitment confirmation? Our HVAC parts team is available to verify compatibility before you purchase — same-day shipping on all in-stock orders.