OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3PNA048130AB

This is the factory OEM Direct Spark Ignition (DSI) Control Board (part number LH33WP003) for the Carrier PY3PNA048130AB packaged rooftop unit. As the brain of the heating system, this microprocessor-based board orchestrates the entire ignition sequence — managing the spark igniter, gas valve, combustion blower, and indoor fan motor. It also continuously monitors flame sensing and safety timing, triggering a hard lockout if an unsafe condition is detected. Common failure symptoms include a no-heat call with no spark, repeated ignition attempts followed by lockout, erratic blower behavior, or a system that starts and immediately shuts down.

• Part Number: LH33WP003 (also supersedes LH33WP003A) | Factory OEM — direct-fit, no modifications required
• Function: Controls combustion sequence, spark ignition, gas valve operation, blower/indoor motor staging, flame sensing, trial-for-ignition timing, and safety lockout logic
• Install Difficulty: 3/5 — Disconnect power and gas before beginning. Tools needed: 1/4" and 5/16" nut drivers, needle-nose pliers, phone camera (photograph all wiring harness connections before removal). Transfer wiring harnesses one connector at a time to avoid mis-wiring.
• Warranty: 1-year OEM factory warranty against manufacturing defects. Ships same business day from our warehouse.

Compatibility: Engineered as the factory-specified replacement for Carrier model PY3PNA048130AB packaged rooftop units. Also fits select Bryant and Day & Night units sharing the LH33WP003/3A board platform — verify your unit's data plate and existing board part number before ordering. Our HVAC parts specialists are available to confirm fitment prior to purchase. Order now — in stock and ships today.