OEM Carrier Transformer 120V–24V 40VA for Model TCHC1150HEFMRADC601

This is the factory OEM replacement transformer (part number HT01BD702) for the Carrier TCHC1150HEFMRADC601. The control transformer steps down line voltage (120V primary) to the 24V secondary signal used by your thermostat, control board, contactor coil, and all low-voltage safety circuits. When this transformer fails, the entire control circuit goes dead — the thermostat goes blank, the system won't respond to any call for heating or cooling, and no safety or staging functions can operate. A failed transformer is one of the most common causes of a completely unresponsive HVAC system.

• Specs: 120V primary | 24V secondary | 40VA rating | Terminal or lead-wire connection | Factory-matched to Carrier OEM control circuit requirements
• OEM vs Generic: This OEM unit is wound and rated to exact Carrier factory specifications. Generic transformers frequently carry inaccurate VA ratings, which can cause nuisance tripping, overheating, or premature control board failure due to voltage sag under load.
• Install Difficulty: 2/5 — Always disconnect power at the breaker before replacing. Tools needed: flathead and Phillips screwdriver, multimeter (to confirm 24V output post-install), wire nuts or spade terminals. Label or photograph all wiring connections before disconnecting the old unit.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed as a direct OEM replacement for the Carrier TCHC1150HEFMRADC601. Verify your unit's data plate and existing transformer VA/voltage ratings before ordering. Our parts specialists are available to confirm fitment — contact us before you order if you have any questions.