OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1RPA120180ABWB

This is the genuine OEM Carrier Direct Spark Ignition (DSI) control board, part number LH33WP003, factory-specified for the Carrier PY1RPA120180ABWB packaged rooftop unit. As the brain of your system's heating sequence, this integrated furnace control (IFC) board manages spark ignition timing, gas valve activation, inducer and blower motor operation, flame sensing, and safety lockout logic. When it fails, symptoms include no-heat calls, ignition lockouts after a trial-for-ignition, intermittent blower faults, or a completely unresponsive unit despite normal thermostat signals.

• Specs: Direct Spark Ignition (DSI) control | Microprocessor-based logic | 24V control circuit input | Onboard LED fault code diagnostics | Factory OEM part number LH33WP003
• OEM vs Generic: This is a genuine Carrier OEM board — not an aftermarket substitute. OEM boards are programmed to exact factory timing tolerances for ignition trials, blower delays, and safety lockout sequences. Aftermarket alternatives may use broader tolerances that can cause nuisance lockouts or accelerate wear on connected components such as the gas valve and inducer motor.
• Install Difficulty: 3/5 — Disconnect power and gas supply before beginning. Document all wiring connector positions with photos prior to removal. Tools needed: #2 Phillips screwdriver, 1/4" and 5/16" nut drivers, needle-nose pliers. Clear any stored fault codes after installation and verify ignition sequence through a full heat call cycle.
• Warranty: 1-year OEM manufacturer warranty. In-stock and ships same business day from our climate-controlled warehouse.

Compatibility: Designed for the Carrier PY1RPA120180ABWB packaged rooftop unit. Always verify the OEM part number on your existing board's label before ordering, as control board revisions (e.g., LH33WP003A) may apply to your specific unit serial range. Need help confirming fitment? Our HVAC parts specialists verify compatibility before you order — no guesswork.