OEM Carrier 40VA Control Transformer for Model C4850C50ZG070600

This OEM control transformer (part# HT01BD236) is the factory-specified replacement for the Carrier C4850C50ZG070600 packaged unit. The transformer steps down line voltage (120V primary) to the 24V secondary signal that powers your thermostat, control board, and all low-voltage safety circuits. When this component fails, absolutely nothing responds — no thermostat display, no contactor pull-in, no ignition sequence. It is often the first component to inspect when a system goes completely silent with no fault codes.

• Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01BD236 | Factory-matched impedance and thermal protection rating for Carrier packaged equipment
• OEM vs Generic: The OEM HT01BD236 transformer is wound to Carrier's exact VA rating and insulation class, ensuring the 24V circuit holds steady voltage under full load. Generic transformers frequently sag under load, causing nuisance lockouts and shortened control board life.
• Install difficulty: 2/5 — Disconnect power at the disconnect and verify zero voltage with a multimeter before proceeding. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label all 24V wiring connections before removing the old transformer. A blown fuse on the secondary side often accompanies transformer failure — inspect the control board fuse before powering back up.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier C4850C50ZG070600 packaged gas/electric unit. Verify your unit's data plate lists a 40VA, 120V/24V transformer before ordering. Cross-reference OEM part number HT01BD236 to confirm fitment. Have questions about compatibility? Our HVAC parts specialists verify fitment before you order — reach out before purchasing if unsure.