Fenwal 35-655706-021 Ignition Control

The Fenwal 35-655706-021 is a microprocessor-based Hot Surface Ignition (HSI) control module designed for high-performance gas-fired equipment. This 120VAC Fenwal ignition module features a 4-second heat-up time and a 4-second Trial for Ignition (TFI) period, providing precise burner management. Engineered for safety and reliability, it operates with three ignition trials before entering a lockout state, ensuring robust flame monitoring and preventing hazardous gas accumulation. This specific unit is configured without a prepurge (No PP), making it an ideal replacement ignition board for specific commercial and industrial HVACR applications requiring immediate activation. By utilizing advanced flame rectification technology, the 35-655706-021 maintains system stability even under fluctuating demand. Whether you are performing a Fenwal 35-655706-021 troubleshooting routine or a standard system upgrade, this control offers the diagnostic accuracy and durability expected by master technicians in the field.

• Precise Ignition Timing: Features a fixed 4-second HSI heat-up and a 4-second TFI to ensure efficient combustion cycles.
• Multi-Trial Logic: Includes a three-try ignition sequence to maximize uptime while maintaining strict safety protocols.
• Industry Compatibility: Designed for seamless integration into 120VAC systems requiring high-amperage HSI performance.
• Diagnostic Reliability: Microprocessor control provides consistent flame sensing and rapid response to signal loss.

What is the purpose of the 'No PP' designation?
The 'No PP' indicates there is no pre-purge cycle. The unit initiates the hot surface igniter immediately upon the call for heat, which is critical for systems with external purge controls or specific mechanical requirements.

Can this control replace a 24VAC Fenwal module?
No, this is a 120VAC dedicated control. Always verify the input voltage and terminal configurations against the original wiring schematic to prevent board failure.

What triggers the lockout mode?
The module enters lockout if a flame is not sensed within the three-try ignition sequence or if the flame signal is lost and cannot be re-established during the subsequent trials.

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.