OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1RPA048115AAWB

This is the genuine OEM Carrier Direct Spark Ignition (DSI) control board, part number LH33WP003, factory-specified for the Carrier PY1RPA048115AAWB packaged rooftop unit. As the central brain of the heating system, this microprocessor-based board orchestrates the entire combustion sequence — controlling the spark igniter and gas valve, managing blower and indoor motor operation, and continuously monitoring flame sensing, trial-for-ignition timing, and safety lockout conditions. When this board fails, common symptoms include a complete no-heat situation, repeated ignition lockouts, erratic blower behavior, or a system that sparks but never establishes a flame.

• OEM Part Number: LH33WP003 (also supersedes LH33WP003A) | Direct Spark Ignition (DSI) type | Microprocessor-based combustion sequencer | Factory-matched for Carrier PY1RPA048115AAWB
• OEM vs Generic: This genuine Carrier OEM board is pre-calibrated to factory ignition timing and lockout thresholds. Aftermarket boards may use generic timing sequences that cause nuisance lockouts, misfire conditions, or shortened heat exchanger life — always choose OEM for commercial rooftop applications.
• Install Difficulty: 4/5 — Control board replacement on a packaged rooftop unit requires disconnecting 120V and 24V wiring harnesses, documenting all connector positions before removal, and verifying proper DIP switch or jumper settings on the new board. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter, camera or phone for wiring photos. Recommend a qualified HVAC technician for this repair.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before 3PM local time.

Compatibility: Engineered as the direct OEM replacement for Carrier model PY1RPA048115AAWB packaged rooftop units. Also fits additional Carrier, Bryant, and ICP rooftop platform models that use the LH33WP003/LH33WP003A board — verify your unit's data plate and existing board part number before ordering. Our HVAC parts specialists are available to confirm fitment. Order now — in stock and ships today.