OEM Carrier 40VA Control Transformer for Model PY3GNA024060NA

The Carrier HT01BD209 is the factory-specified step-down control transformer for the PY3GNA024060NA packaged unit. It converts 120V line voltage to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When this transformer fails, the entire system goes dark: the thermostat loses power, no heating or cooling calls are processed, and the unit will not respond at all. A blown transformer is often the result of a shorted downstream component, so inspect the control circuit for faults before installing the replacement.

• Specs: 120V primary | 24V secondary output | 40VA rating | Factory OEM part number HT01BD209 | Direct plug-in wiring harness connector
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage specifications. Generic aftermarket units frequently underperform their rated VA, causing nuisance trips, overheating, and premature control board failure — especially under full heating load.
• Install Difficulty: 2/5 — Shut off power at the disconnect and breaker before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Always identify and correct any downstream short before energizing the new transformer.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Designed for the Carrier PY3GNA024060NA packaged unit. Verify primary voltage (120V) and VA rating on your unit's data plate before ordering. Not sure if this is the right part? Our HVAC parts specialists verify fitment before you buy — reach out before placing your order.