OEM Carrier Control Transformer 40VA 120V/24V for Model PY3GNA060115NB

This OEM replacement transformer (part# HT01BD209) is the factory-specified control circuit transformer for the Carrier PY3GNA060115NB gas furnace. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, gas valve, and all low-voltage safety circuits. When this part fails, the entire control circuit goes dark — the system will not call for heat, the thermostat display may go blank, and no components will respond. A failed transformer is often identified by measuring 0V AC at the secondary terminals with line voltage confirmed at the primary.

• Specs: 120V primary | 24V secondary | 40VA rated | Single-phase | Meets OEM factory tolerances for the PY3GNA060115NB platform
• OEM vs Generic: This is a genuine Carrier OEM part (HT01BD209), wound to exact VA rating and insulation class. Generic transformers may be under-rated in actual VA output, causing overheating or nuisance tripping of the built-in thermal fuse under normal load.
• Install Difficulty: 2/5 — Disconnect power at the breaker and confirm zero voltage before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label all low-voltage wiring before disconnecting from terminal block. Standard wire-nut or terminal connections; no soldering required.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Designed as the direct OEM replacement for the Carrier PY3GNA060115NB packaged gas/electric unit. Always verify your existing transformer's primary voltage, secondary voltage, and VA rating against your unit's data plate before ordering. Have a question about fitment? Our HVAC parts specialists verify compatibility before you buy — reach out before placing your order.