Fenwal 35-679655-551 Control

The Fenwal 35-679655-551 Ignition Control is a heavy-duty, microprocessor-based hot surface ignition (HSI) module engineered for commercial and industrial gas-fired appliances with combustion chambers exceeding 400,000 BTU. Operating on a 24 VAC input, this control provides precise timing sequences for pre-purge, inter-purge, and post-purge cycles, ensuring volatile gases are cleared before and after the trial for ignition (TFI). As a CSD-1 compliant device, it meets rigorous ASME safety standards for boilers and high-capacity burners, featuring an integrated combustion blower relay and continuous monitoring of the pressure switch and flame status.

Designed for maximum uptime in demanding environments, the 35-679655-551 includes a local reset function, allowing technicians to clear lockouts directly at the unit. This proven HSI control utilizes microprocessor logic for repeatable performance and multi-trial ignition attempts. The diagnostic LED indicator facilitates rapid troubleshooting by signaling specific fault codes, such as airflow issues or flame failure, reducing diagnostic time for HVACR contractors. Its robust construction and conformal coating provide moisture resistance and durability in high-BTU industrial heating applications.

Key Benefits for Contractors:

• ASME CSD-1 Compliance: Meets essential safety requirements for commercial boiler and water heater installations.
• Proven HSI Technology: Ensures the ignition source is verified before the gas valve opens, preventing unburned gas accumulation.
• Diagnostic LED Interface: Simplifies service calls with clear flash codes for internal failure, ignition lockout, and 24 VAC low voltage.
• Local Reset Capability: Minimizes system downtime by allowing manual reset at the control board without cycling the high-side power.
• High-Capacity Compatibility: Optimized for large-scale commercial heating systems and industrial process equipment.

Common Questions:

Is this control compatible with LP gas applications?
Yes, the Fenwal 35-679655-551 is compatible with natural, LP, and manufactured gases, provided the system is configured correctly for the fuel type.

What does the local reset feature do?
The local reset allows a technician to manually clear an ignition lockout at the module, which is a requirement for certain CSD-1 compliant safety protocols.

Can this replace a standard 35-67 series module?
While it shares the 35-67 architecture, this specific model is CSD-1 compliant and features Proven HSI; always verify the technical specifications and terminal configurations of your existing controller before installation.

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.