Fenwal 35-679652-551 Control

The Fenwal 35-679652-551 is a robust 24VAC direct spark ignition (DSI) control module engineered for commercial and industrial atmospheric burners. Designed for precision flame rectification, this microprocessor-based controller features a single-try ignition sequence with a 15-second trial for ignition (TFI) and a 30-second pre-purge period. The unit utilizes a multi-pin connector for seamless integration into existing HVAC control systems and provides internal diagnostic LED signaling for rapid troubleshooting of lockout conditions or flame loss. This specific model supports local sensing and is built with high-temperature tolerant components to maintain stable burner sequencing. For technicians performing field replacements, ensure the spark gap and flame rod positioning meet OEM specifications to prevent nuisance lockouts. This ignition board provides critical safety lockout logic to prevent unburned fuel accumulation, ensuring the appliance operates within narrow combustion safety parameters under various load conditions.

Technical Benefits

• Enhanced Safety Logic: Features lockout/flame loss protection that immediately terminates gas flow if no flame is detected during the 15-second TFI.
• Efficient Sequencing: Integrated 30-second pre-purge ensures the combustion chamber is cleared of residual gases before the spark ignition sequence initiates.
• Reliable Diagnostics: Built-in LED indicators simplify fault code identification, reducing diagnostic time for field contractors on service calls.
• System Compatibility: Operates on standard 24VAC ignition control circuits, making it a versatile component for commercial heating repair and boiler maintenance.

Common Questions

What does a single-try lockout mean for system operation?
In a single-try ignition system, the module attempts to light the burner once; if flame rectification is not established within the 15-second window, the module enters a hard lockout to ensure safety. Power must be cycled to reset.

Can this board be used for both LP and Natural Gas systems?
Yes, the Fenwal 35-67 controller is designed for DSI gas furnace applications regardless of fuel type, provided the gas valve and burner orifices are configured correctly by the manufacturer.

How do I troubleshoot a 35-679652-551 lockout?
First, verify the igniter spark gap and ensure the sense electrode is clean. Check for consistent 24VAC at the input terminals and confirm the grounding circuit is secure, as poor grounding is a primary cause of flame signal failure.

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.