Fenwal 35-705501-105 Control

The Fenwal 35-705501-105 is a 120V Direct Spark Ignition (DSI) control specifically engineered for high-demand gas-fired equipment. This microprocessor-based module is a standard for technicians servicing commercial cooking appliances, boilers, and infrared heaters that require an HVAC 120V ignition board with precise timing. This specific Fenwal ignition control replacement is configured for a single ignition attempt (1 Try), featuring a 15-second prepurge to clear the combustion chamber and a 10-second Trial for Ignition (TFI) period. The Fenwal 35-70 series uses proprietary Detect-A-Flame technology for remote flame sensing, ensuring the gas valve remains energized only when a flame is rectified. With a wide operating temperature range of -40°F to 175°F and multi-enclosure compatibility, this 120V gas burner control provides on-board diagnostics via an LED indicator to quickly identify flame faults or internal failures. It is polarity insensitive, which simplifies HVAC DSI troubleshooting and reduces the risk of wiring errors during field installation.

Key Benefits

• Precision Timing: Microprocessor circuitry ensures consistent 15-second purge and 10-second ignition sequences for improved safety.
• Simplified Diagnostics: On-board LED provides specific error codes, drastically reducing downtime during service calls.
• Versatile Compatibility: Designed for use with Natural, LP, and Manufactured gases across various industrial heating applications.
• Robust Construction: Engineered to withstand extreme vibrations and temperature fluctuations common in commercial environments.
• Flame Safety: Integrated remote flame sensing with a minimum 1.0 μA flame current requirement for reliable lockout prevention.

Common Questions

What is the reset procedure after a lockout occurs?
For this single-try model, recovery from a safety lockout requires a manual reset. This is achieved by either adjusting the thermostat below the ambient temperature or removing the 120V power supply for at least 5 seconds.

Can this control be used for local flame sensing?
While the 35-70 series supports multiple configurations, this specific model (35-705501-105) is typically utilized with remote flame sensing electrodes to provide accurate rectification in the burner flame envelope.

What do the LED flash codes signify?
The diagnostic LED typically indicates three primary conditions: steady on for internal control failure, two flashes for a false flame signal detected during purge, and three flashes for an ignition lockout after the trial for ignition fails.

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.