OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3PPA042090NB

This is the factory OEM Direct Spark Ignition (DSI) control board for the Carrier PY3PPA042090NB packaged rooftop unit. The DSI control board is the nerve center of your system's heating operation — it orchestrates spark ignition, gas valve activation, combustion blower sequencing, indoor fan motor control, and continuous flame sensing. When it fails, you'll typically experience a no-heat condition, repeated ignition lockouts with no spark, a system that starts then immediately shuts down, or an unresponsive blower that never stages on. LED fault codes on the board itself can help pinpoint the exact failure mode before replacement.

• Part Type: Direct Spark Ignition (DSI) Integrated Circuit Control Board | OEM Part # LH33WP003 | Fits Carrier PY3PPA042090NB rooftop packaged unit
• OEM vs Generic: This is a genuine Carrier OEM board manufactured to original factory specifications. Aftermarket boards may not replicate proprietary timing sequences, flame-sensing sensitivity, or safety lockout logic — risking nuisance trips, voided warranties, or unsafe operation. OEM is always the recommended replacement for control boards.
• Install Difficulty: 3/5 — Disconnect power and gas before beginning. Tools needed: Phillips and flathead screwdrivers, needle-nose pliers, smartphone (to photograph all wiring harness connections before removal). Transfer all harness connectors one-by-one to avoid miswiring. Verify all safety interlocks are reconnected before restoring power.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our stocked warehouse.

Compatibility: Engineered as a direct OEM replacement for Carrier model PY3PPA042090NB. Always cross-reference your unit's data plate and existing board part number before ordering to confirm fitment. Our HVAC parts specialists are available to verify compatibility before you buy — no guesswork required. Order today and your part ships same business day.