Fenwal 35-705500-001 Control

The Fenwal 35-705500-001 is a 120VAC Direct Spark Ignition (DSI) control module engineered for precise burner sequencing in commercial and residential gas-fired equipment. This microprocessor-based ignition control operates with a 4-second Trial for Ignition (TFI) period, making it a critical component for systems requiring rapid flame establishment. Designed for efficiency, this unit features a single-try ignition sequence and does not include a pre-purge (NoPP) cycle, allowing for immediate spark delivery upon a call for heat. As a robust HVAC replacement part, it utilizes solid-state circuitry to monitor flame sensing via ionization, ensuring reliable gas valve control and safe operation. When troubleshooting DSI ignition failure, this Fenwal module provides a direct OEM cross-reference for various food service and hydronic heating applications. Contractors should verify line voltage 120V input and spark electrode gap settings to ensure optimal combustion system performance and prevent nuisance lockouts during high-demand cycles.

• Precise 4-Second TFI: Ensures rapid flame rectification and minimizes unburned gas accumulation during start-up.
• Dedicated 120VAC Operation: Optimized for high-voltage DSI systems without the need for additional step-down transformers.
• Compact Microprocessor Design: Provides consistent ignition sequencing and resistance to environmental vibration and thermal stress.
• Direct OEM Compatibility: Streamlines the HVAC repair process by fitting standard mounting footprints in commercial appliances.

What happens if the Fenwal 35-705500-001 fails to sense flame after the 4-second TFI?
This 1-try ignition control will immediately enter a lockout state. You must cycle the thermostat call for heat or remove input power to reset the module after verifying the flame sensor probe and electrode alignment.

Can this module be used in systems requiring a pre-purge cycle?
No, this specific 35-70 Series control is a "NoPP" (No Pre-Purge) model. If your combustion blower requires time to clear the heat exchanger before ignition, you must use a module with a defined pre-purge delay.

Is the 35-705500-001 compatible with 24V gas valves?
No, this is a 120V DSI control. Ensure the solenoid gas valve and power supply match the 120VAC rating to avoid catastrophic board 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.