OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY3PPA048115NB

This is the genuine OEM Carrier Direct Spark Ignition (DSI) Control Board, part number LH33WP003, factory-specified for the Carrier PY3PPA048115NB packaged rooftop unit. As the central brain of your unit's heating system, this microprocessor-based board manages the full ignition sequence — from spark ignition and gas valve activation to blower motor control, inducer motor supervision, flame sensing, and safety lockout. When this board fails, symptoms typically include a no-heat condition, repeated ignition lockout, short-cycling, erratic fan behavior, or the system failing to advance past the pre-purge stage.

• Specs: Direct Spark Ignition (DSI) microprocessor-based control | Manages spark igniter, gas valve, combustion blower, and indoor blower motor | Monitors limit switches, flame sensor, and safety circuits | Integrated LED fault-code diagnostics for fast field troubleshooting | Pre-purge: 45 sec | Trial for ignition: 5+2 sec | Retry interval: 20 sec for 15 min | Manual-reset lockout
• OEM vs Generic: This is the genuine Carrier factory part — not an aftermarket substitute. OEM boards are programmed to exact Carrier ignition timing, flame-sensing thresholds, and lockout sequences. Aftermarket boards may deviate from factory parameters, risking nuisance lockouts, voided equipment warranties, or unsafe operation.
• Install Difficulty: 4/5 — Disconnect all power before servicing. Tools needed: ¼" nut driver, Phillips screwdriver, needle-nose pliers, multimeter. Photograph or label all wiring harness connections before removal. Verify 24V control power is present before condemning the board. Recommended for qualified HVAC technicians only.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier PY3PPA048115NB packaged rooftop unit. Cross-references include suffix variant LH33WP003A. Always verify your existing board's part number on the board label or unit data plate before ordering. Our HVAC parts specialists are available to confirm fitment — contact us before you order if you have any questions.