OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1PPA048120AFBA

This is the genuine OEM Direct Spark Ignition (DSI) control board for the Carrier PY1PPA048120AFBA packaged gas/electric unit. As the brain of the heating system, this microprocessor-based board orchestrates the entire combustion sequence — controlling the spark igniter, gas valve, combustion blower, and indoor blower motors while continuously monitoring flame sensing, trial-for-ignition timing, and safety lockout conditions. When this board fails, symptoms typically include a complete no-heat condition, repeated ignition lockout faults, erratic short-cycling, or the system failing to advance past the inducer pre-purge stage.

• Part Number: LH33WP003 (also supersedes LH33WP003A) | OEM-matched microprocessor logic | Direct Spark Ignition (DSI) architecture
• OEM vs Generic: This factory-original board uses Carrier-validated firmware and timing sequences. Aftermarket boards may deviate in trial-for-ignition timing and lockout logic, risking nuisance faults or unsafe operation. OEM is always the recommended replacement for combustion control.
• Install Difficulty: 3/5 — Disconnect power and gas before servicing. Tools needed: 1/4" and 5/16" nut drivers, needle-nose pliers, smartphone for wiring photo. Label all connector positions before removal. Always verify 24V control circuit integrity after installation.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our climate-controlled warehouse.

Compatibility: Factory-specified replacement for Carrier model PY1PPA048120AFBA packaged units. Also fits select Bryant and Payne rooftop and packaged gas units using the LH33WP003/LH33WP003A control board. Verify your existing board's part number on the board label before ordering. Not sure it fits? Our HVAC parts specialists confirm fitment before you buy — contact us before placing your order.