OEM Carrier Transformer 120V–24V 40VA for Model PY3GEAA36090AA

This OEM replacement transformer (part number HT01BC701) is the factory-specified control circuit transformer for the Carrier PY3GEAA36090AA packaged unit. The transformer steps down 120V line voltage to the 24V signal voltage that powers your thermostat, control board, and all low-voltage switching components. When the transformer fails, the entire control circuit goes dark — your thermostat becomes unresponsive, contactors won't energize, and the system produces no heating or cooling whatsoever. It is one of the most overlooked yet most critical components in the unit.

• Specs: Primary voltage: 120V AC | Secondary voltage: 24V AC | VA rating: 40VA | Factory-matched OEM tolerances | Includes integral secondary circuit protection
• OEM vs Generic: This OEM Carrier part (HT01BC701) is wound to exact factory VA and voltage tolerances. Generic transformers may run under-rated VA, causing overheating, nuisance tripping, or premature failure of downstream control boards.
• Install difficulty: 2/5 — Disconnect all power at the disconnect box and verify zero voltage with a multimeter before handling. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter, wire nuts or fork terminals. Always label low-voltage wiring (R, C, G, W, Y) before disconnecting the old unit.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Orders placed before 3 PM local time ship same business day from our warehouse.

Compatibility: Engineered as a direct OEM replacement for the Carrier PY3GEAA36090AA packaged unit. Confirm your unit's data plate shows a 120V primary / 24V secondary control transformer before ordering. Not sure if this fits? Our HVAC parts specialists verify fitment before you buy — contact us anytime.