OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3GNA030040AB

This OEM Direct Spark Ignition (DSI) control board is the factory-specified replacement for the Carrier PY3GNA030040AB packaged heating and cooling unit. The DSI control board serves as the brain of the heating sequence — it orchestrates inducer startup, spark ignition timing, flame verification, gas valve activation, and system fault lockout logic. When this board fails, common symptoms include a complete no-heat condition, repeated ignition lockouts, failure to prove flame even when the igniter and flame sensor test good, or erratic short-cycling that cannot be traced to any individual component.

• Specs: Direct Spark Ignition (DSI) control architecture | OEM part number LH33WP003 | Factory-matched to Carrier PY3GNA030040AB | Integrated fault code LED diagnostics | 24V control circuit compatible
• OEM vs Generic: This is a genuine OEM Carrier board — identical firmware, relay ratings, and terminal layout to what left the factory. Aftermarket boards frequently carry mismatched timing sequences and lower-rated relays, risking nuisance lockouts and premature gas valve failure.
• Install Difficulty: 4/5 — Control board replacement requires de-energizing the unit at the disconnect and breaker, photographing or labeling ALL wiring connections before removal, and verifying input/output voltages after reinstallation. Tools needed: multimeter, 1/4" and 5/16" nut drivers, needle-nose pliers, and a phone or camera for wiring documentation. Professional installation is recommended.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Engineered specifically for Carrier model PY3GNA030040AB packaged units. Always cross-reference the OEM part number LH33WP003 printed on your existing board before ordering to confirm an exact match. Have questions about fitment? Our HVAC parts specialists verify compatibility before you buy — contact us before placing your order.