Fenwal 35-705500-105 Control

The Fenwal 35-705500-105 is a robust 120VAC direct spark ignition (DSI) control module engineered for precise gas burner management in commercial and industrial HVACR equipment. Featuring a 10-second trial for ignition (TFI) and a 15-second prepurge cycle, this Fenwal ignition control ensures safe and reliable combustion sequences. This microprocessor-based controller utilizes a single-try ignition sequence and is designed for non-volatile lockout, requiring a manual reset or power cycle if the flame is not sensed. For contractors performing a Fenwal 35-70 series replacement, this unit offers high-voltage spark generation and monitoring with integrated flame sensing circuitry. As a critical component in many furnace ignition systems, the 35-705500-105 supports localized or remote flame sensing, making it a versatile HVAC replacement part for diverse burner configurations. Ensure your application requires the standard 120V input for both the control logic and the gas valve output before installation.

• Precise Timing: Factory-set 10-second TFI and 15-second prepurge optimize burner safety and efficiency.
• Diagnostic Reliability: Built-in LED diagnostics facilitate rapid Fenwal 35-705500-105 troubleshooting in the field.
• Multi-Input Compatibility: Operates on standard 120VAC line voltage for streamlined integration into existing control circuits.
• Robust Construction: Enclosed design protects sensitive electronic components from ambient contaminants in harsh mechanical rooms.

How do I reset the Fenwal 35-705500-105 after a lockout?
Since this is a single-try, non-volatile lockout module, you must interrupt the 120V power supply to the control for at least 5 seconds to reset the internal logic.

Can this control be used with both Natural Gas and LP systems?
Yes, the module is fuel-neutral; however, your gas valve and burner orifices must be properly configured for the specific fuel type being used.

What is the purpose of the 15-second prepurge?
The prepurge cycle ensures any residual gas or combustion products are cleared from the combustion chamber before the direct spark ignition trial begins, preventing delayed ignition or "booming."

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.