OEM Carrier Control Transformer 40VA 120V/24V for Model CGH12520D — Part HT01BC116

This is the OEM factory-replacement control transformer for the Carrier CGH12520D unit, sold under part number HT01BC116. The transformer steps down 120V line voltage to the 24V signal voltage that powers your thermostat, control board, contactor coil, and all low-voltage safety circuits. When this component fails, the entire control circuit goes dark — the thermostat becomes unresponsive, the system will not heat or cool, and no error codes will display because the board itself has lost power.

• Specs: Input: 120V AC | Output: 24V AC | Capacity: 40VA | OEM Part Number: HT01BC116 | Factory-matched to Carrier CGH12520D specifications
• OEM vs Generic: This OEM transformer is wound and insulated to Carrier's exact VA rating and thermal limits. Generic substitutes frequently run under-rated VA, causing premature burnout under normal heating and cooling demand cycles — especially in systems with multiple low-voltage accessories.
• Install difficulty: 2/5 — Turn off all power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire nuts or spade connectors, multimeter to confirm 24V output after installation. Label all wiring before disconnecting the old transformer.
• Warranty: 1-year OEM manufacturer warranty. Orders placed before cutoff ship same business day from our climate-controlled warehouse.

Compatibility: Designed and tested for the Carrier CGH12520D. Always verify your unit's data plate voltage requirements before ordering. If your system uses 208/240V primary input, do not order this unit — confirm input voltage with a multimeter at the transformer primary leads. Our fitment team is available to verify compatibility before you purchase. Order today and get same-day shipping — back in comfort fast.