OEM Carrier Control Transformer 40VA for Model C48A405062

This OEM control transformer is the factory-specified replacement for the Carrier C48A405062 packaged unit. The transformer steps down 120V line voltage to the 24V signal required by your thermostat, contactor coil, and control board. When it fails, the entire control circuit goes dead — your thermostat goes blank, nothing responds to a call for heating or cooling, and the system will not start at all. Replacing the transformer is often the fastest and most affordable fix for a completely unresponsive HVAC system.

• Specs: 40VA rating | 120V primary / 24V secondary | Compatible OEM part numbers: HT01BD236 and HT01BD702 | Factory-matched output voltage tolerance
• OEM vs Generic: OEM transformers are wound and insulated to Carrier's exact VA and voltage specifications. Generic units frequently run outside rated VA, causing nuisance tripped fuses, premature control board failures, and voided equipment warranties.
• Install difficulty: 2/5 — Disconnect power at the disconnect box and verify zero voltage with a multimeter before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label all 24V secondary wires before disconnecting. Check and replace the 3A control fuse on the board if the transformer blew due to a short.
• Warranty: 1-year OEM factory warranty. Orders placed before cutoff ship same business day from our climate-controlled warehouse.

Compatibility: Designed for the Carrier C48A405062 packaged unit. Cross-references OEM part numbers HT01BD236 and HT01BD702 — both numbers confirm fitment for this model. Always verify your existing transformer's VA rating and primary/secondary voltages on the data plate or wiring diagram before ordering. Our parts specialists are available to confirm fitment prior to purchase — reach out before you order and we'll make sure it's right.