OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1PJB048115NBAA

This is the genuine OEM Direct Spark Ignition (DSI) control board for the Carrier PY1PJB048115NBAA packaged rooftop unit. As the brain of the heating system, this microprocessor-based board orchestrates the entire combustion sequence — controlling the spark igniter and gas valve, managing blower and indoor fan motors, monitoring trial-for-ignition timing, performing flame sensing, and triggering safety lockout when an unsafe condition is detected. When this board fails, the most common symptoms are a complete no-heat condition, repeated ignition lockout codes, short-cycling after ignition attempts, or erratic blower behavior that cannot be resolved by resetting the system.

• OEM Part Number: LH33WP003 (also supersedes LH33WP003A) | Direct Spark Ignition (DSI) type | Microprocessor-based logic control
• OEM vs Generic: This is a genuine Carrier OEM board — factory-programmed with exact timing, lockout, and flame-sensing parameters for the PY1PJB048115NBAA. Aftermarket boards may substitute but can introduce timing variances that cause nuisance lockouts or reduce system lifespan.
• Install Difficulty: 3/5 — Requires disconnecting 24V control wiring, line voltage harnesses, and gas valve leads. Document all wiring connections with photos before removal. Tools needed: 1/4" and 5/16" nut drivers, needle-nose pliers, multimeter. Recommended for qualified HVAC technicians.
• Warranty: 1-year OEM factory warranty. In stock — ships same business day from our warehouse.

Compatibility: Engineered as the factory-specified replacement for Carrier model PY1PJB048115NBAA rooftop packaged units. Always verify your existing board's part number against LH33WP003 or LH33WP003A before ordering. Need fitment confirmation? Our HVAC parts specialists verify compatibility before you buy — contact us today.