Carrier LH33WZ512 Ignition Module

The Carrier LH33WZ512 Ignition Module is a critical intermittent pilot (IID) control engineered to manage the ignition sequence for residential and commercial HVAC furnaces, boilers, and air handlers. As a direct OEM replacement for the LH33WZ512A, LH33WZ512B, and ICM296, this microprocessor-based module ensures precise spark ignition and flame supervision. It operates on a standard 24V AC (19-31 VAC) input and delivers a high-voltage spark output (17.5 kV minimum) to ignite the pilot burner. The unit features a safety lockout mechanism (5–6 minute delay) that prevents dangerous gas accumulation by shutting down the system after repeated ignition proving failures. Designed for natural gas and propane applications, this spark ignition control maintains system efficiency across popular models like the 58GS and 394GAZ series. Technicians should verify flame sensor grounding and 24V signal at the gas valve when troubleshooting common ignition lockout codes.

• Universal Compatibility: Serves as the factory-authorized direct replacement for outdated LH33WZ512A and LH33WZ512B units, plus the ICM296.
• Enhanced Safety: Integrated 100% shut-off lockout prevents hazardous conditions during flame failure or unsuccessful trials for ignition.
• Heavy-Duty Spark Output: Delivers a consistent 17.5 kV spark to ensure reliable combustion in both LP and Natural Gas systems.
• Rugged Construction: Built to withstand high-vibration and high-heat environments typical of furnace burner compartments.

• What does Carrier Error Code 34 mean? This indicates an ignition proving failure, often caused by a dirty flame sensor, low gas pressure, or a faulty LH33WZ512 module.
• How do I reset the ignition lockout? After three failed attempts (Code 14), the module enters a 3-hour lockout. You can force a reset by cycling the 24V power for 60 seconds.
• Can this replace a standing pilot system? No, the LH33WZ512 is specifically for intermittent pilot (IID) systems and requires a 24V electronic ignition setup.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.