OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3GNA042090AB

This is the genuine OEM Direct Spark Ignition (DSI) control board for the Carrier PY3GNA042090AB packaged gas/electric unit. As the brain of the furnace section, this microprocessor-based board orchestrates the entire heating sequence — controlling the combustion process, blower and indoor fan motors, spark igniter, and gas valve, while continuously monitoring timing, trial-for-ignition cycles, flame sensing, and safety lockout conditions. When this board fails, symptoms typically include a no-heat lockout, repeated ignition attempts with no flame establishment, erratic blower behavior, or a complete system shutdown with no response to thermostat calls for heat.

• OEM Part Number: LH33WP003 (also covers LH33WP003A suffix revision) | Direct Spark Ignition (DSI) type | Factory-matched for Carrier PY3GNA042090AB packaged units
• Board Functions: Controls spark igniter sequencing, gas valve operation, blower motor timing, and safety sensor monitoring — shuts system down automatically upon detecting unsafe conditions to prevent hazards
• Install Difficulty: 3/5 — Requires shutting off gas and electrical supply before servicing. Tools needed: Phillips and flathead screwdrivers, needle-nose pliers, multimeter for 24V control circuit verification. Photograph all wiring harness connections before disconnecting. Note LED fault codes on the old board before removal for diagnostics reference.
• Warranty & Shipping: 1-year OEM factory warranty against defects. In stock — ships same business day from our warehouse.

Compatibility: Designed as the factory-specified replacement for Carrier model PY3GNA042090AB. Also compatible with other Carrier, Bryant, and Payne packaged rooftop and combination units sharing the LH33WP003/LH33WP003A board specification. Always verify your existing board's part number on the label before ordering. Our fitment team is available to confirm compatibility — contact us before you order if you have any questions.