OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY2PPB048090AA

This OEM Carrier control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY2PPB048090AA packaged unit. The transformer steps down line voltage from 208/240V to the 24V required by the low-voltage control circuit, powering the thermostat, control board, gas valve, and all safety relays. When this transformer fails — due to a short in the secondary circuit, overload, or age — the entire control system goes dark: no thermostat response, no ignition sequence, and no heating or cooling whatsoever.

• Specs: Input voltage: 208/240V | Output voltage: 24V | Frequency: 50/60 Hz | Power rating: 40VA | Factory OEM part #HT01BD209
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances specified by Carrier engineering. Undersized or off-tolerance aftermarket units can overheat, trip repeatedly, or fail to properly power multi-stage controls — shortening the life of your control board.
• Install difficulty: 2/5 — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, needle-nose pliers. Label all low-voltage wires before disconnecting. Verify fuse on secondary circuit and replace if blown before installing new transformer.
• Warranty: 1-year OEM factory warranty. In stock — ships same business day from our warehouse.

Compatibility: Direct OEM replacement for Carrier PY2PPB048090AA packaged gas/electric units. Always verify your unit's data plate voltage matches the 208/240V primary specification before ordering. Have a question about fitment? Our HVAC parts specialists confirm compatibility before you buy — call or chat today.