OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1PNA048120AEBA

This is the genuine OEM Direct Spark Ignition (DSI) control board for the Carrier PY1PNA048120AEBA packaged unit. Acting as the brain of your heating system, this microprocessor-based board orchestrates the entire combustion sequence — controlling the spark igniter, gas valve, blower motor, and indoor fan motor while continuously monitoring flame sensing, safety lockout timing, and trial-for-ignition sequences. When this board fails, symptoms typically include a no-heat condition, repeated ignition lockouts, short cycling, or a blower that runs but never fires the burner.

• OEM Part Number: LH33WP003 (also covers LH33WP003A revision) | Direct Spark Ignition (DSI) microprocessor-based control | Factory-original Carrier specification for model PY1PNA048120AEBA
• OEM vs Generic: This factory-original board is pre-calibrated to exact Carrier ignition timing, lockout delay, and blower-off delay parameters. Aftermarket boards may use approximate timing that accelerates heat exchanger fatigue and can cause nuisance lockouts not present with the OEM board.
• Install Difficulty: 3/5 — Requires shutting off gas supply and 120V power at the disconnect before beginning. Tools needed: #2 Phillips screwdriver, 1/4" nut driver, needle-nose pliers, camera or phone to photograph all wiring harness connections before removal. Note and transfer all DIP switch settings from the original board to the replacement.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Ships same business day from our stocked warehouse.

Compatibility: Engineered as the factory-specified DSI control board replacement for Carrier model PY1PNA048120AEBA. Always verify the part number printed on your existing board before ordering. Not sure it fits? Our HVAC parts team confirms fitment before you buy — contact us with your full model and serial number.