Lochinvar & A.O. Smith 100109872 Ignition Control

The Lochinvar & A.O. Smith 100109872 Ignition Control is a critical integrated controller designed for precise sequence management in high-efficiency water heaters and boilers. This authentic OEM component is a direct replacement for legacy part numbers 9004470205 and 190714-000, ensuring full compatibility with existing hot surface ignition (HSI) systems. This module manages the combustion process by supervising the inducer motor, gas valve, and flame sensing circuits. Its microprocessor-controlled logic provides advanced flame rectification sensing to prevent short-cycling and ensure safe operation during high-demand cycles. For contractors servicing Lochinvar Knight or A.O. Smith Cyclone series, this board is essential for resolving ignition lockout errors and communication failures. Integrating this control ensures the system maintains its original thermal efficiency and safety parameters without the risks associated with universal aftermarket alternatives.

• Direct OEM Replacement: Replaces cross-referenced parts 9004470205 and 190714-000 without wiring modifications.
• Enhanced Diagnostics: Integrated logic assists in troubleshooting intermittent ignition failures and airflow switch issues.
• Robust Construction: Engineered to withstand the high ambient temperatures common in sealed combustion chambers.
• Precise Timing: Features factory-calibrated trial-for-ignition (TFI) and pre-purge sequencing for optimal combustion safety.

Common Technical Questions

How do I troubleshoot a lockout on this ignition module?
Verify the 120V power supply to the inducer and check for a consistent microamp signal at the flame sensor. If the controller fails to initiate the hot surface igniter despite closed pressure switches, the internal relay may be compromised.

Is this control compatible with both natural gas and liquid propane units?
Yes, the 100109872 governs the ignition sequence regardless of gas type, provided the gas valve and orifices are correctly configured for the specific fuel source.

Does this module replace the Fenwal or Honeywell versions used in older boilers?
This specific part is the designated successor for A.O. Smith and Lochinvar systems using the 100109872 configuration. Always verify the part number on the existing board to ensure terminal alignment.

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.