OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY2PNB042090NB

This is the factory OEM Direct Spark Ignition (DSI) Control Board (Part # LH33WP003) for the Carrier PY2PNB042090NB packaged rooftop unit. As the central brain of your heating system, this integrated furnace control board manages and sequences every critical ignition and safety function. When this board fails, you may experience a complete no-heat condition, repeated ignition lockouts, erratic blower behavior, or a system that starts briefly and then shuts down without producing heat. Fault codes displayed via onboard LED indicators often point directly to this board as the root cause.

• Part Specifications: OEM Part # LH33WP003 | Direct Spark Ignition (DSI) microprocessor-based control | Manages spark ignition, gas valve activation, combustion blower, and indoor fan motors | Integrated flame sensing and safety lockout logic | Status LED diagnostic indicators for rapid fault-code identification
• OEM vs. Generic: This is a genuine Carrier OEM board manufactured to original factory design standards, ensuring full electrical and mechanical compatibility with the PY2PNB042090NB. Aftermarket boards (such as ICM291 equivalents) may lack exact timing sequences and safety interlock thresholds, potentially voiding equipment warranties and creating callback risk on commercial rooftop units.
• Install Difficulty: 3/5 — This repair is best performed by a licensed HVAC technician. Required tools: 1/4" and 5/16" nut drivers, needle-nose pliers, multimeter (24VAC and 120VAC ranges), camera or phone to photograph all wiring harness connections before removal. Always disconnect power at the disconnect box and verify zero voltage before handling the board. Re-enable power only after all harness connectors are fully seated.
• Warranty: Backed by Carrier's OEM factory warranty. Ships same business day from our stocked warehouse — no waiting on special orders.

Compatibility: Engineered as the direct factory replacement for the Carrier PY2PNB042090NB packaged rooftop gas/electric unit. This board is also compatible with select other Carrier, Bryant, and Payne rooftop models that share the LH33WP003 specification — verify your unit's data plate and existing board part number before ordering. Our HVAC parts specialists are available to confirm fitment before you buy. Order now — in stock and ships today.