OEM Carrier 40VA Control Transformer for Model C4850C50AJ05061

This OEM replacement transformer (part number HT01BD236) is the factory-specified control circuit transformer for the Carrier C4850C50AJ05061 packaged unit. The transformer steps down 120V line voltage to 24V AC to power the low-voltage control circuit — including the thermostat, contactor coil, and control board. When it fails, nothing in the system responds: the thermostat goes blank, the unit won't energize, and you may measure 0V on the 24V secondary terminals. A failed transformer is often caused by a short in the control wiring or a failed component drawing excess current.

• Specs: 40VA rated | 120V primary / 24V secondary | OEM part number HT01BD236 | Factory-matched impedance and thermal protection
• OEM vs Generic: This is the factory OEM transformer engineered specifically for the Carrier C4850C50AJ05061. Generic transformers may share a VA rating but often lack proper thermal cutoffs and impedance matching, risking repeat failure or downstream control board damage.
• Install difficulty: 2/5 — Disconnect power at the breaker and verify zero voltage before touching any wiring. Tools needed: flathead and Phillips screwdriver, multimeter, wire stripper. Always check for downstream shorts in control wiring before installing the new transformer to prevent immediate re-failure.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C4850C50AJ05061 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering. If you're unsure of fitment or have a related model number, our HVAC parts specialists will confirm compatibility before your order ships — same-day on orders placed before 3PM.