OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1PPA036080ACBA

This is the OEM factory-specified Direct Spark Ignition (DSI) Control Board for the Carrier PY1PPA036080ACBA packaged gas/electric rooftop unit. The DSI control board is the brain of the heating system — it manages spark ignition sequencing, gas valve activation, inducer and blower fan motor operation, flame sensing, and safety switch monitoring. When this board fails, you'll typically experience a no-heat condition, a hard lockout after one or more failed ignition attempts, or erratic short-cycling that won't resolve with a simple reset. LED fault codes on the board help pinpoint the exact failure mode during diagnostics.

• Part Function: Microprocessor-based DSI control — manages spark igniter firing, gas valve open/close timing, trial-for-ignition sequencing, inducer fan pre-purge and post-purge, blower motor staging, and continuous flame rod monitoring with automatic safety lockout.
• OEM vs. Generic: This is a genuine Carrier OEM board (part LH33WP003) manufactured to exact factory tolerances. OEM boards preserve original ignition timing parameters and safety lockout thresholds. Aftermarket boards may require reconfiguration and can introduce timing drift that accelerates heat exchanger wear.
• Install Difficulty: 3/5 — Disconnect power and gas before servicing. Tools needed: 1/4" and 5/16" nut drivers, needle-nose pliers, multimeter, camera/phone to photograph all wiring harnesses prior to disconnection. Follow the unit's wiring diagram on the door panel during reinstallation. Always clear fault codes and perform a full ignition test cycle after replacement.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Engineered as the direct replacement for Carrier PY1PPA036080ACBA packaged rooftop units. Also cross-references part number LH33WP003A. Verify your existing board's part number on its label before ordering to confirm fitment. Have questions about compatibility? Our HVAC parts specialists verify fitment before every order — contact us today and get your unit back online fast.