OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3PPA048090AA

This is the genuine OEM Carrier LH33WP003 Direct Spark Ignition (DSI) Control Board, the factory-specified replacement for the Carrier PY3PPA048090AA packaged rooftop unit. The DSI control board is the nerve center of your unit's heating system — it manages the spark igniter, gas valve, combustion sequence, blower motor timing, flame sensing, and safety lockout logic. When this board fails, symptoms typically include a hard lockout with no ignition attempt, the unit firing briefly then shutting down on flame-sensing failure, or a complete loss of heating with no error codes advancing past the ignition trial period.

• Part Number: LH33WP003 (also supersedes LH33WP003A) | Direct Spark Ignition (DSI) microprocessor-based control | Carrier OEM factory specification
• OEM vs Generic: This OEM board is factory-programmed with exact timing parameters for ignition trial, flame-sensing thresholds, and lockout sequencing. Aftermarket boards may use generic timing that causes nuisance lockouts, voided equipment warranties, or unsafe combustion behavior.
• Install Difficulty: 3/5 — Disconnect power and gas before servicing. Tools needed: 1/4" and 5/16" nut drivers, needle-nose pliers, multimeter, phone/camera to document wiring harness connections. Transfer wiring harnesses one connector at a time to avoid miswiring. Verify 24V control circuit integrity after installation before restoring gas.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our stocked warehouse — no special-order delays.

Compatibility: Designed for the Carrier PY3PPA048090AA packaged rooftop unit. The LH33WP003 is a common rooftop ignition control used across multiple Carrier and Bryant commercial packaged platforms — always verify your existing board's part number against the data plate before ordering. If you need fitment confirmation, our HVAC parts specialists verify compatibility before your order ships.