OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY2PPB042090NB

This is the genuine OEM Carrier Direct Spark Ignition (DSI) control board, part number LH33WP003, factory-specified for the Carrier PY2PPB042090NB packaged rooftop unit. The DSI control board is the brain of your unit's heating system — it orchestrates spark ignition sequencing, gas valve activation, combustion blower operation, indoor fan staging, flame sensing, and safety lockout logic. When this board fails, common symptoms include a complete no-heat condition, ignition lockout after a failed trial, the system starting then shutting off within seconds, or erratic blower behavior that won't resolve with a simple reset.

• Part Type & Specs: Direct Spark Ignition (DSI) Integrated Control Board | Microprocessor-based | Controls combustion sequencing, spark igniter, gas valve, blower motor, and indoor fan | Monitors trial-for-ignition timing, flame sensing, and safety lockout — OEM part number LH33WP003
• OEM vs Generic: This is a genuine Carrier OEM board engineered to original factory design specifications, ensuring full compatibility and preserving system integrity. Aftermarket boards (e.g., ICM291) may function as drop-in replacements but can vary in fault-code behavior, LED diagnostics, and lockout timing — which matters for warranty and service records.
• Install Difficulty: 3/5 — Requires disconnecting 24V control wiring, line-voltage connectors, and grounding screws. Always shut off power at the disconnect and tag out before servicing. Photograph all wire harness connections before removal. Tools needed: 1/4" and 5/16" nut drivers, needle-nose pliers, and a multimeter to verify 24V control power before condemning the board.
• Warranty & Shipping: 1-year OEM manufacturer warranty against defects. In stock and ships same business day from our warehouse. Every order is verified for fitment before it leaves our facility.

Compatibility: Engineered for the Carrier PY2PPB042090NB packaged rooftop gas/electric unit. Always cross-reference the part number on your existing board's label before ordering — variants such as LH33WP003A may apply. Not sure if this is your board? Our HVAC parts specialists will verify fitment at no charge before you order.