OEM Carrier 40VA Control Transformer HT01BC116 for Model GA1AAD036050ABJA

This OEM control transformer (part number HT01BC116) is the factory-specified replacement for the Carrier GA1AAD036050ABJA packaged unit. The transformer steps down 120V line voltage to the 24V signal voltage that powers your thermostat, control board, contactor coil, and every low-voltage safety circuit in the system. When the transformer fails, nothing responds — the thermostat goes dark, the contactor won't pull in, and the unit sits completely dead even though line power is present. A blown transformer is also a common symptom of a downstream short in the 24V circuit, so always check secondary-side current draw before replacing.

• Specs: 40 VA rating | Primary: 120V | Secondary: 24V | Factory-matched to OEM control board requirements | Replaces OEM part number HT01BC116
• OEM vs Generic: This is the exact factory unit — correct VA rating, terminal footprint, and mounting configuration. Undersized generic transformers overheat and fail prematurely, and an incorrect VA rating can starve multi-stage controls of the current they need to operate reliably.
• Install difficulty: 2/5 — Shut off all power before proceeding. Tools needed: multimeter (verify 24V output and check for secondary shorts first), 1/4" nut driver, small flat-head screwdriver for terminal screws. Photograph all low-voltage wiring before disconnecting. Confirm secondary circuit is clear of shorts before powering up the replacement.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered for the Carrier GA1AAD036050ABJA packaged unit. Verify your existing transformer's VA rating and primary/secondary voltages on the unit data plate or existing part label before ordering. Need help confirming fitment? Our HVAC parts specialists verify compatibility before your order ships — no guesswork required.