OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3PNA048090AB

This is the OEM factory-specified Direct Spark Ignition (DSI) Control Board for the Carrier PY3PNA048090AB packaged rooftop unit. As the brain of the heating system, this microprocessor-based board manages the complete combustion sequence — controlling the spark igniter and gas valve, monitoring flame sensing, timing trial-for-ignition, and triggering safety lockout if an unsafe condition is detected. When this board fails, symptoms typically include a no-heat condition, repeated ignition lockout faults, erratic blower operation, or the unit failing to respond to thermostat calls for heat.

• OEM Part Number: LH33WP003 (also covers LH33WP003A) | Direct Spark Ignition (DSI) type | Microprocessor-based combustion controller | Factory-matched to Carrier PY3PNA048090AB specifications
• OEM vs Generic: This is the genuine Carrier OEM board — not an aftermarket substitute. OEM boards ensure exact timing sequences, lockout logic, and connector compatibility, preventing secondary failures caused by mismatch in ignition trial timing or blower delays.
• Install Difficulty: 3/5 — Disconnect power and gas before beginning. Tools needed: 1/4" and 5/16" nut drivers, needle-nose pliers, smartphone (photo all wiring harnesses before disconnecting). Label every connector. Verify all safety lockout LED codes before and after replacement to confirm diagnosis.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Engineered for the Carrier PY3PNA048090AB packaged rooftop unit. Replaces OEM part numbers LH33WP003 and LH33WP003A. Confirm your existing board's part number on the label before ordering. Have questions about fitment? Our HVAC parts specialists verify compatibility before every order — contact us and we'll confirm before you buy.