OEM Carrier 40VA Control Transformer HT01CN236 for Model FK4CNB006000AHAA

This OEM control transformer (part# HT01CN236) is the factory-specified replacement for the Carrier FK4CNB006000AHAA fan coil air handler. The transformer steps down 120V line voltage to 24V AC, powering the entire low-voltage control circuit — including the thermostat, contactor coil, and any connected zone controls. When this component fails, the result is total control loss: your thermostat goes dark, the system ignores calls for heating or cooling, and nothing responds. It is often misdiagnosed as a thermostat or control board failure before the transformer is checked.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Class 2 transformer | Direct OEM replacement for part# HT01CN236
• OEM vs Generic: This factory OEM transformer is wound to exact VA and voltage tolerances for the FK4CNB006000AHAA control board. Generic transformers often under-deliver on VA capacity, causing nuisance trips on the built-in thermal overload — especially when zone boards or accessories are connected.
• Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (verify 0V before touching terminals). Label or photograph existing wire connections before disconnecting the primary and secondary leads.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. In-stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier FK4CNB006000AHAA fan coil air handler. Always verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate before ordering. If you are unsure of fitment, our HVAC parts specialists verify compatibility before you order — no guesswork required.