OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1PNA018040ACBA

This is the genuine OEM Carrier Direct Spark Ignition (DSI) control board, part number LH33WP003, factory-specified for the Carrier PY1PNA018040ACBA packaged rooftop unit. As the central intelligence of your system, this Integrated Furnace Control (IFC) board manages spark ignition sequencing, gas valve activation, combustion blower control, indoor fan motor operation, and continuous flame sensing. When the DSI board fails, the most common symptoms include the unit failing to ignite, shutting down in lockout after one or more ignition attempts, the blower not responding to thermostat calls, or erratic heating cycles with no clear mechanical cause. A faulty board may also produce misleading fault codes that point to other components — always confirm board failure by ruling out the igniter, flame sensor, and pressure switch first.

• Part Type: Direct Spark Ignition (DSI) Integrated Control Board | Microprocessor-based | Status LED fault-code indicators for rapid field diagnostics
• OEM vs Generic: This is a genuine Carrier OEM board manufactured to exact factory tolerances for the PY1PNA018040ACBA. Aftermarket equivalents (e.g., ICM291) may fit but can introduce timing variances in trial-for-ignition and lockout sequences — OEM is always recommended for commercial or warranty-active units.
• Install Difficulty: 3/5 — Disconnect power and gas before servicing. Photograph all wiring harness connections before removal. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, smartphone for wiring documentation. Label every connector. Refer to unit wiring diagram located inside the access panel.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Engineered as the direct OEM replacement for Carrier model PY1PNA018040ACBA. Always verify the part number on your existing board's label before ordering — cross-reference with your unit's wiring diagram for full confirmation. Need help verifying fitment? Our HVAC parts specialists confirm compatibility before you order — no guesswork, no returns.