OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3PNA042090NB

This is the genuine OEM Carrier Direct Spark Ignition (DSI) Control Board, part number LH33WP003, factory-specified for the Carrier PY3PNA042090NB packaged unit. The DSI control board serves as the brain of your furnace or packaged gas heating system — it sequences the ignition process, monitors safety sensors (including pressure switches, limit switches, and flame sensing), and triggers a system lockout if an unsafe condition is detected. Common failure symptoms include a system that sparks but never lights, a unit that locks out after one or two ignition attempts, error codes on the board's diagnostic LED, or a complete no-heat condition with no response from the heating circuit.

• Specs: 24 VAC control voltage | 208/230 VAC 60Hz system power | Direct Spark Ignition (DSI) sequence | Integrated diagnostic LED fault codes | OEM part numbers: LH33WP003 / LH33WP003A
• OEM vs Generic: This OEM board is factory-programmed with exact ignition timing, lockout retry logic, and safety thresholds for the Carrier PY3PNA042090NB. Aftermarket boards may use generalized timing that can cause nuisance lockouts or, worse, unsafe ignition delays — always prefer OEM for gas-ignition control.
• Install difficulty: 3/5 — Requires shutting off gas supply and 24V/line-voltage power before beginning. Photograph all wiring harness connections and connector positions before removal. Tools needed: flat-head and Phillips screwdrivers, 1/4" nut driver, needle-nose pliers. Always restore and verify gas connections before test firing. Professional installation recommended.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Engineered and factory-matched for the Carrier PY3PNA042090NB packaged gas/electric unit. Also cross-references to LH33WP003A and ICP part number 1068-83-119A. Verify your existing board's part number on the label before ordering. Have a question about fitment? Our HVAC parts team confirms compatibility before you buy — contact us today.