OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3GNA048115NA

The Carrier HT01BD209 is the factory-specified 40VA step-down control transformer for the PY3GNA048115NA packaged HVAC unit. This transformer converts the line-voltage power supply (208/240V primary) down to the 24V AC signal that powers the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When this transformer fails, the system goes completely silent: no thermostat display, no blower, no heating or cooling response. A failed transformer is often traced to a shorted control wire or a failed component that caused an overcurrent event, so always inspect the control circuit before installing the replacement.

• Specs: OEM Part # HT01BD209 | Input: 208/240V AC | Output: 24V AC | Rating: 40VA | Frequency: 50/60 Hz | Factory-matched to Carrier PY3GNA048115NA
• OEM vs Generic: This is the genuine Carrier OEM transformer, wound and insulated to factory specifications. Generic transformers rated at 40VA can exhibit voltage sag under full control-circuit load, leading to erratic thermostat behavior or nuisance lockouts — a risk the OEM unit eliminates.
• Install Difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter (to verify 24V output and check for control circuit shorts before energizing). Always inspect low-voltage wiring for chafing or shorts prior to installation.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Fits Carrier model PY3GNA048115NA packaged HVAC unit. Verify your unit's data plate voltage ratings (208/240V primary, 24V secondary, 40VA) before ordering. Not sure it's the right part? Our HVAC parts specialists are available to confirm fitment before you buy — call or chat today for same-day shipping assistance.