Fenwal 35-705501-505 Control

The Fenwal 35-705501-505 is a robust 120VAC Direct Spark Ignition (DSI) control module engineered for high-demand gas-fired applications including commercial cooking equipment, boilers, and water heaters. As a veteran-grade HVAC ignition module, it utilizes microprocessor-based circuitry to provide precise, repeatable timing for critical combustion sequences. This specific configuration features a 10-second Trial for Ignition (TFI) and a 5-second pre-purge cycle, ensuring the combustion chamber is cleared before the spark ignition sequence begins. Designed for versatility, it supports remote flame sensing—utilizing flame rectification technology to monitor burner stability with a minimum sensitivity of 0.7µA. The board includes on-board LED diagnostics to streamline troubleshooting on the job site, reducing downtime by identifying lockout conditions or hardware faults instantly. With a polarity insensitive design and flame current test pins, this controller is built to withstand extreme environments ranging from -40°F to 175°F, making it a reliable choice for gas valve control in specialized heating systems.

• Enhanced Safety: Integrated 5-second pre-purge clears residual gases, while the 10-second TFI ensures controlled burner startup.
• Diagnostic Precision: The system diagnostic LED provides clear error codes (e.g., 3 flashes for ignition lockout), eliminating guesswork during service calls.
• Flexible Monitoring: Supports remote sensor configurations, allowing for improved flame signal accuracy in complex burner geometries.
• Field Reliability: Microprocessor control delivers consistent timing regardless of ambient temperature or voltage fluctuations within the 102-138 VAC range.
• Technician Friendly: Features flame current test points for immediate signal strength verification with a standard DC microammeter.

What does a steady LED light on the Fenwal 35-705501-505 indicate?
A steady on LED typically signals an internal hardware or software fault. If cycling the 120V power does not clear this state, the module generally requires replacement.

Can this module replace a local sense ignition control?
Yes, but since this and other Fenwal 35-70 series models use remote sensing, you may need to adjust your electrode wiring to utilize a separate sense rod rather than the spark electrode for flame detection.

Is the Fenwal 35-705501-505 compatible with LP gas?
Affirmative. This DSI control is designed for use with Natural, LP, or manufactured gas systems, provided the gas valve and burner assembly are properly rated for the fuel type.

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.