OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3GNA042060NB

This is the genuine OEM Carrier Direct Spark Ignition (DSI) control board (part number LH33WP003), the factory-specified replacement for the Carrier PY3GNA042060NB packaged rooftop unit. The DSI control board is the operational brain of your heating system — it sequences the entire ignition cycle, commands gas valve activation, monitors flame sensing, controls the blower and indoor fan motors, and manages inducer motor operation. When this board fails, symptoms include a complete no-heat condition, repeated ignition lockout faults, furnace short-cycling, or the system failing to progress past the inducer pre-purge stage.

• Part Number & Electrical Specs: OEM Part # LH33WP003 (also supersedes LH33WP003A) | 24 VAC control voltage | 208/230 VAC 60Hz power input | Direct Spark Ignition (DSI) type
• Key Functions: Manages spark ignition sequencing, gas valve activation, flame rod signal processing, blower/fan motor staging, induction motor control, and safety lockout with LED fault code diagnostics for faster field troubleshooting
• OEM vs. Generic: This factory-authorized OEM board is manufactured to Carrier's original design standards, ensuring full pin-for-pin connector compatibility and preserving system safety interlocks. Aftermarket boards may omit diagnostic LED functionality and carry wider electrical tolerances that can stress downstream components.
• Install Difficulty: 3/5 — Requires de-energizing and locking out the unit before opening the control panel. Tools needed: flat-head and Phillips screwdrivers, needle-nose pliers, a phone or camera to photograph all wiring harness connections before removal. Reconnect harnesses per original routing; misrouted wiring can trigger false fault codes. Recommend an HVAC-certified technician for installation.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Direct factory replacement for the Carrier PY3GNA042060NB packaged rooftop unit. Also fits additional Carrier, Bryant, and ICP family rooftop models — verify your OEM part number on the unit's data plate before ordering. Not sure if this is the right board? Our HVAC parts specialists verify fitment before you order — contact us anytime.