OEM Carrier Direct Spark Ignition (DSI) Control Board LH33WP003 for Model PY2PNB024040AA

This is the genuine OEM Carrier Direct Spark Ignition (DSI) control board, part number LH33WP003, factory-specified for the Carrier PY2PNB024040AA packaged rooftop unit. As the central brain of your heating system, this microprocessor-based board manages the entire ignition sequence — from spark ignition and gas valve activation to blower motor control, inducer fan sequencing, and flame sensing. When it fails, symptoms typically include a no-heat lockout condition, repeated ignition attempts with no flame establishment, or the system failing to advance past pre-purge — leaving your building without heat.

• Specs: Direct Spark Ignition (DSI) microprocessor control | Manages spark igniter, gas valve, combustion blower, and indoor fan motor | Integrated LED fault-code diagnostics | Monitors limit switches, flame sensing, and safety lockout | Compatible with 24V control circuit
• OEM vs Generic: This is the genuine Carrier factory part — not an aftermarket substitute. OEM boards are programmed to exact timing sequences (pre-purge, trial for ignition, retry, lockout) that aftermarket boards may approximate but not perfectly replicate, risking nuisance lockouts or warranty voids.
• Install difficulty: 3/5 — Requires disconnecting 24V control wiring harness and line-voltage connections. Always shut off power at the disconnect and gas supply before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter, phone camera to photograph all wiring before removal. Recommend licensed HVAC technician for rooftop unit service.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Designed for the Carrier PY2PNB024040AA packaged rooftop unit. Verify your existing board's part number against LH33WP003 or cross-reference LH33WP003A before ordering. Not sure? Our HVAC parts specialists verify fitment at no charge — contact us before you buy.