OEM Carrier Control Transformer 40VA for Model C4850C48AY05061

This OEM Carrier control transformer (part# HT01BD236) is the factory-specified replacement for the C4850C48AY05061 packaged unit. The transformer steps down 120V line voltage to the 24V signal used by your thermostat, contactor coil, and control board. When it fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to any calls for heating or cooling, and no fault codes will display because there's no power to generate them.

• Specs: 40VA rated | 120V primary / 24V secondary | Class 2 control circuit transformer | OEM part number HT01BD236 | Factory-matched output tolerance
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances required by the Carrier control circuit. Undersized or off-tolerance generic units can brown out under load, causing intermittent lockouts, nuisance trips on other components, or premature contactor coil failure.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Label all low-voltage wiring before disconnecting. Verify 24V output with a meter before restoring the system to operation.
• Warranty: 1-year OEM factory warranty. In-stock units ship same business day from our warehouse when ordered before 3PM local time.

Compatibility: Designed for the Carrier C4850C48AY05061 packaged unit. Always verify the transformer's VA rating and primary/secondary voltages against your unit's wiring diagram and data plate before ordering. If you're unsure of fitment, our HVAC parts specialists can confirm compatibility before you buy — just reach out before placing your order.