OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY1RPA048074AAWA

This is the genuine OEM Carrier Direct Spark Ignition (DSI) control board, part number LH33WP003, factory-specified for the Carrier PY1RPA048074AAWA packaged rooftop unit. As the central intelligence of the heating system, this microprocessor-based board manages spark ignition sequencing, gas valve activation, combustion blower control, indoor fan motor operation, flame sensing, and safety lockout logic. When this board fails, typical symptoms include a complete no-heat condition, repeated ignition lockout faults, short-cycling, or the unit failing to advance past the trial-for-ignition stage. Fault codes displayed via onboard LED indicators will help pinpoint the failure during diagnosis.

• Part Type: Direct Spark Ignition (DSI) Integrated Control Board | OEM Part # LH33WP003 | Also supersedes LH33WP003A
• OEM vs Generic: This is the factory Carrier OEM board — engineered to exact timing, flame-sensing thresholds, and safety lockout specifications for the PY1RPA048074AAWA. Aftermarket substitutes may exhibit mis-timed ignition trials, nuisance lockouts, or incompatible blower delay profiles that shorten system life.
• Install Difficulty: 3/5 — Requires disconnecting 120V line power and 24V control wiring. Tools needed: flat-head and Phillips screwdrivers, needle-nose pliers, multimeter. Photograph all harness connections before removal. Verify all safety interlocks are reconnected before restoring power. Recommended for qualified HVAC technicians.
• Warranty: 1-year OEM factory warranty. In stock — ships same business day from our warehouse.

Compatibility: Designed for the Carrier PY1RPA048074AAWA packaged rooftop gas/electric unit. Verify your unit's data plate and existing board part number before ordering. Cross-references include LH33WP003A. Have a question about fitment? Our HVAC parts specialists confirm compatibility before you buy — contact us today and get your system back online fast.