OEM Carrier Transformer 40VA 120V to 24V for Model C48A302064

This is the factory OEM replacement transformer (part number HT01BD702) for the Carrier C48A302064 packaged unit. The transformer steps down 120V line voltage to the 24V used by your thermostat, control board, contactor coil, and all other low-voltage control circuit components. When this transformer fails, the entire control circuit goes dead — your thermostat goes blank, the system won't respond to any commands, and nothing turns on. It is often the first component to check when a system is completely unresponsive despite the disconnect being powered.

• Specs: 40VA capacity | 120V primary input | 24V secondary output | Class 2 rated | Direct OEM replacement for part number HT01BD702
• OEM vs Generic: This OEM unit is wound and insulated to Carrier's exact factory specifications, ensuring proper VA capacity and thermal protection. Undersized or off-brand transformers can overheat, blow internal fuses, or fail to supply adequate current to multi-stage systems.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper. Use your multimeter to confirm 0V at the transformer terminals before touching any wiring. Photograph existing wiring connections before removal.
• Warranty: 1-year OEM factory warranty against defects. Orders placed by 3PM local time ship same business day from our HVAC parts warehouse.

Compatibility: Designed as a direct OEM replacement for the Carrier C48A302064 packaged unit. Always verify your existing transformer's VA rating and primary/secondary voltages against your unit's wiring diagram before ordering. If you have questions about fitment, our parts specialists can confirm compatibility before you buy — same-day shipping available on all in-stock OEM transformers.