Lochinvar & A.O. Smith 100109976 Control Board

The Lochinvar & A.O. Smith 100109976 Control Board is a critical integrated electronic control module designed for high-efficiency boilers and commercial water heaters. This OEM replacement part acts as the central microprocessor, managing ignition sequences, flame proving, and safety limit monitoring. It is a direct successor to the AO Smith 9004600205, ensuring backward compatibility with legacy systems. The addition of the cable assembly harness simplifies field installation, reducing downtime during critical repairs. By regulating the combustion air blower and gas supply, this board maintains precise temperature set points and optimizes the firing rate for maximum fuel efficiency. As a veteran technician knows, using genuine 100109976 HVAC controls is the only way to ensure the Smart System interface functions correctly with 0-10 VDC BMS inputs and cascade sequencing. This board provides robust operational status monitoring for pre-purge, ignition, and post-purge cycles to maintain 120V system reliability.

Key Benefits for Technicians:

• Plug-and-Play Integration: Includes the full cable assembly to eliminate wiring errors and speed up component replacement.
• Advanced Diagnostics: Fully supports Smart System 2-line LCD displays for real-time fault code tracking and troubleshooting.
• Enhanced Safety Protocols: Continuous flame monitoring and hardware-level safety checks for blocked drains and low gas pressure.
• Universal Commercial Reliability: Engineering-grade microprocessor platform designed to handle the variable loads of Lochinvar Copper-Fin II units.

Common Questions:

Is the 100109976 compatible with older A.O. Smith models?
Yes, this 100109976 control board is the designated replacement for the obsolete 9004600205 harness and board combo, maintaining all original logic and terminal configurations.

What does it mean if my display shows a 'Flame Failure' fault?
This often indicates the integrated control module isn't receiving a signal from the flame sensor or igniter. Check the cable assembly connections first before determining if the board's ignition circuit has failed.

Does this board support BMS communication?
Yes, it allows for 0-10 VDC input for Building Management System integration, enabling remote set point adjustment and status monitoring.

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.