OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1PJB048090NBAA

This is the factory OEM Direct Spark Ignition (DSI) Control Board (part number LH33WP003) for the Carrier PY1PJB048090NBAA packaged gas/electric unit. As the brain of the heating system, this microprocessor-based board orchestrates the entire combustion sequence — controlling the spark igniter and gas valve, monitoring trial-for-ignition timing, supervising flame sensing, and initiating safety lockout when an unsafe condition is detected. When this board fails, common symptoms include: no-heat calls with ignition lockout fault codes, the system starting then shutting down within seconds (flame-sense failure), blower or inducer motor not responding, or a completely unresponsive unit with no LED fault codes at all.

• OEM Part Number: LH33WP003 (also supersedes LH33WP003A) | Factory-direct replacement, no modifications required
• Board Functions: Controls combustion sequence, spark igniter, gas valve, blower motor, and indoor motor | Monitors ignition trial timing, flame sensing, and safety lockout per factory logic
• Install Difficulty: 3/5 — Disconnect power and gas before beginning. Tools needed: 1/4" and 5/16" nut drivers, needle-nose pliers, phone or camera to photograph all wiring harness connections prior to removal. Transfer wiring harness connectors one at a time to avoid miswiring.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Factory-matched for Carrier model PY1PJB048090NBAA packaged rooftop unit. Also fits select Carrier, Bryant, and Payne packaged units sharing the LH33WP003/LH33WP003A board specification — verify your unit's part number on the control board or data plate before ordering. Our HVAC parts team is available to confirm fitment before you purchase.