Fenwal 35-705505-113 Control

The Fenwal 35-705505-113 is a microprocessor-based Direct Spark Ignition (DSI) control engineered for high-precision management of 120V gas-fired equipment. Constructed to replace legacy analog systems, this module provides superior timing accuracy (typically ±5%) for critical combustion sequences. This specific 35-70 series configuration features a 15-second pre-purge to clear the combustion chamber of residual gases before ignition and a 7-second trial for ignition (TFI) window. To minimize nuisance lockouts in demanding environments, the 35-705505-113 is programmed for 3 ignition trials with inter-purge cycles, ensuring reliable flame establishment for both natural and LP gas applications.

For service contractors, this unit simplifies field diagnostics with an on-board diagnostic LED that provides real-time fault codes. The polarity insensitive design reduces the risk of miswiring during installation, while integrated flame current test pins allow for rapid signal verification using a standard DC micro-ammeter. Designed for versatility, the control handles local sense (single spark and sense) configurations and is encased in a robust enclosure suitable for temperatures ranging from -40°F to 175°F. Whether you are servicing commercial cooking equipment, unit heaters, or infrared burners, this 120VAC ignition module delivers the repeatable performance required for code-compliant burner operation.

• Enhanced Reliability: Microprocessor logic ensures consistent 15s pre-purge and 7s TFI timings regardless of ambient conditions.
• Efficient Troubleshooting: Diagnostic LED and dedicated test pins allow for instant flame signal monitoring and error code identification.
• Reduced Lockouts: The 3-try ignition sequence provides multiple attempts to prove flame before entering a safe lockout state.
• Durable Construction: Built to withstand vibration and moisture, making it an ideal choice for gas-fired appliance environments.
• Universal Fuel Compatibility: Fully compatible with Natural Gas, LP, and Manufactured Gas systems.

What is the purpose of the 15-second pre-purge?
The 15-second pre-purge is a safety sequence that runs the combustion blower to exhaust any unburned gas from the heat exchanger before the spark electrode is energized.

How do I test the flame signal on this module?
You can measure the flame sense signal using the FC+ and FC- test pins. A reading of 1.0 µA DC or higher is required for stable operation; the 35-705505-113 design is polarity insensitive to help maintain this signal.

Can this replace older Fenwal analog controls?
Yes, the 35-70 series is the designated successor to several legacy 120V models (such as the 05-14 and 05-38), offering a smaller footprint and significantly better timing accuracy for direct spark ignition.

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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.