OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3PNA048115AB

This is the genuine OEM Carrier LH33WP003 Direct Spark Ignition (DSI) Control Board — the factory-specified replacement for the Carrier PY3PNA048115AB packaged rooftop unit. The DSI control board is the central intelligence of your gas heating system: it orchestrates spark ignition, gas valve activation, combustion blower sequencing, indoor fan motor staging, and real-time flame sensing. When this board fails, you'll typically experience a hard lockout after a failed ignition attempt, a unit that starts briefly then shuts down, erratic blower behavior, or a completely non-responsive heating system.

• Part Specs: OEM Part# LH33WP003 | Direct Spark Ignition (DSI) microprocessor-based integrated circuit board | Factory-matched to Carrier PY3PNA048115AB | Includes LED status indicator for fault code diagnostics
• OEM vs Generic: The genuine Carrier LH33WP003 is engineered to exact factory specifications, ensuring precise ignition timing, flame-sensing thresholds, and motor staging sequences. Aftermarket boards may exhibit timing drift or incompatible lockout logic — risking repeat service calls and compounding warranty issues.
• Install Difficulty: 3/5 — Requires disconnecting 24V control wiring, line-voltage motor leads, and gas valve terminals. Always power down the unit at the disconnect and tag out before removal. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Photograph all wiring harnesses before disconnecting. Recommend professional installation.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered for the Carrier PY3PNA048115AB packaged rooftop unit. This board controls combustion, blower and indoor motors, spark ignition, gas valve operation, and flame sensing with full safety lockout protection. Verify your existing board's part number on the unit's data plate before ordering. Have a question about fit? Our HVAC parts specialists verify compatibility before you order — call or chat today and we'll ship same business day.