OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY2PNB030040NB

This OEM Direct Spark Ignition (DSI) control board is the factory-specified replacement for the Carrier PY2PNB030040NB packaged rooftop unit. The DSI control board is the brain of your unit's heating system — it orchestrates spark ignition sequencing, gas valve activation, blower and indoor fan motor operation, flame sensing, inducer motor control, and safety lockout. When it fails, symptoms typically include a complete no-heat condition, ignition lockout after a trial-for-ignition attempt, the system starting and then immediately shutting down, or erratic blower behavior. Fault codes displayed via onboard LED indicators can pinpoint the exact failure mode before you even order a part.

• Specs: Direct Spark Ignition (DSI) microprocessor-based control | OEM Part # LH33WP003 | Monitors combustion, blower, and indoor fan motors | Manages spark igniter, gas valve, flame sensing, and safety lockout sequences
• OEM vs Generic: This is a genuine Carrier OEM board manufactured to exact factory tolerances and firmware specifications. Aftermarket boards may lack proper timing calibration or full diagnostic LED functionality, risking nuisance lockouts and shortened equipment life.
• Install difficulty: 3/5 — Requires disconnecting 24V control wiring and line-voltage harnesses. Always shut off power at the disconnect and gas supply before servicing. Tools needed: flathead and Phillips screwdrivers, 1/4" nut driver, needle-nose pliers, multimeter. Photograph all wiring connections before removal. Recommended for qualified HVAC technicians.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse — order by 3 PM local time to get it on its way today.

Compatibility: Designed for the Carrier PY2PNB030040NB packaged rooftop unit. Always verify the OEM part number on your existing control board's label before ordering, as board revisions (e.g., LH33WP003A) may apply. Questions about fitment? Our HVAC parts specialists verify compatibility before you buy — contact us before ordering.