OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1RPA072074ACWA

This is the genuine OEM Carrier LH33WP003 Direct Spark Ignition (DSI) Control Board — the factory-specified replacement for the Carrier PY1RPA072074ACWA packaged rooftop unit. The DSI control board is the nerve center of your unit's heating system: it orchestrates spark ignition sequencing, gas valve activation, combustion airflow via the inducer motor, blower and indoor fan motor staging, and continuous flame sensing. When this board fails, you may experience a complete no-heat condition, repeated ignition lockout faults, a unit that starts briefly then shuts down, or a total loss of blower and fan control. LED fault codes on the board itself help pinpoint the failure mode quickly.

• Part Type: Direct Spark Ignition (DSI) Integrated Control Board | OEM Part #: LH33WP003 | Microprocessor-based logic with onboard LED fault-code diagnostics
• OEM vs Generic: This is the genuine Carrier OEM board, manufactured to exact factory specifications. Aftermarket boards may not replicate precise ignition timing windows, flame-sensing sensitivity thresholds, or blower delay sequences — risking nuisance lockouts or reduced equipment life. OEM ensures full compatibility and preserves your unit warranty.
• Install Difficulty: 3/5 — Requires disconnection of 24V control wiring harness, line-voltage connections, and grounding leads. Always shut off power at the disconnect and verify with a meter before touching any terminals. Photograph all wiring prior to removal. Tools needed: flathead and Phillips screwdrivers, ¼" nut driver, needle-nose pliers, multimeter. A qualified HVAC technician is recommended.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Ships same business day from our warehouse when ordered by 3 PM local time.

Compatibility: Designed for the Carrier PY1RPA072074ACWA packaged rooftop unit. The PY prefix designates a Carrier commercial packaged gas/electric rooftop series. Always verify your existing board's part number on the data label before ordering. Not sure it fits? Our HVAC parts specialists verify fitment before you complete your order — contact us anytime.