OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3PNA024060AB

This OEM Direct Spark Ignition (DSI) control board is the factory-specified replacement for the Carrier PY3PNA024060AB packaged rooftop unit. As the brain of the combustion system, this microprocessor-based board orchestrates the entire heating sequence — controlling the spark igniter, gas valve, combustion blower, and indoor fan motor while continuously monitoring flame sensing, trial-for-ignition timing, and safety lockout conditions. When this board fails, common symptoms include a no-heat lockout, repeated ignition attempts with no flame establishment, erratic blower behavior, or a system that powers on but refuses to enter the heating cycle.

• Part Number: LH33WP003 (also supersedes LH33WP003A) | Direct Spark Ignition (DSI) type | Microprocessor-based combustion sequencer | Factory-matched for Carrier rooftop applications
• OEM vs Generic: This is a genuine OEM Carrier board with factory-calibrated ignition timing, trial periods, and lockout thresholds. Aftermarket boards may use wider tolerances that cause nuisance lockouts, premature shutdowns, or unsafe flame-sensing delays — especially in commercial rooftop environments with variable gas pressure.
• Install Difficulty: 3/5 — Requires disconnecting 24V control wiring harnesses, ground leads, and multiple terminal connectors. Always photograph all wiring before removal. Tools needed: 1/4" and 5/16" nut drivers, needle-nose pliers, multimeter for 24V verification post-install. Recommended for qualified HVAC technicians only.
• Warranty: 1-year OEM manufacturer warranty. In-stock and ships same business day from our warehouse — get your unit back online fast.

Compatibility: Designed for the Carrier PY3PNA024060AB packaged rooftop unit. This board replaces both the LH33WP003 and LH33WP003A revisions with no modifications required. Always verify your existing board's part number on the unit data plate or board label before ordering. Our fitment team is available to confirm compatibility before you buy.