OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1RPA090180ACWB

This is the factory OEM Direct Spark Ignition (DSI) control board for the Carrier PY1RPA090180ACWB rooftop unit, supplied under part number LH33WP003. As the central brain of your unit's heating system, this board manages spark ignition sequencing, gas valve activation, combustion blower and indoor fan motor control, flame sensing, and safety lockout logic. When it fails, symptoms typically include a complete no-heat condition, repeated ignition lockout faults, a unit that starts briefly then shuts off, or non-responsive blower operation — all pointing directly to a failed DSI board.

• Specs: Direct Spark Ignition (DSI) microprocessor-based control | Manages combustion, blower, and indoor fan motors | Controls spark igniter and gas valve timing | Integrated flame sensing and safety lockout | Onboard LED status indicators for fault code diagnostics
• OEM vs Generic: This is a genuine Carrier OEM board engineered to exact factory specifications for the PY1RPA090180ACWB. Generic or aftermarket boards may lack full timing calibration and LED diagnostic capability, risking repeated nuisance lockouts or premature failure of connected components such as the gas valve and inducer motor.
• Install difficulty: 3/5 — Requires disconnecting 24V and line-voltage wiring harnesses; photograph all connectors before removal. Tools needed: 1/4" and 5/16" nut drivers, needle-nose pliers, a multimeter for verifying 24V control signal. Always shut off the unit's main disconnect and gas supply before beginning work.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse when ordered before 3PM local time.

Compatibility: Engineered specifically for the Carrier PY1RPA090180ACWB packaged rooftop unit. Verify your unit's data plate matches part number LH33WP003 before ordering. Not sure if this board fits your unit? Our HVAC parts specialists verify fitment before you buy — contact us for confirmation.