Fenwal 35-705506-115 Control

The Fenwal 35-705506-115 is a robust 120V Direct Spark Ignition (DSI) control engineered for precision in gas-fired atmospheric and power burner applications. Built on a microprocessor-based platform, this module manages the gas valve and ignition sequence with a 15-second pre-purge (PP) to clear the combustion chamber and a 10-second trial for ignition (TFI). Designed for high-reliability environments, it features a 3-try ignition sequence with inter-purge, ensuring the system attempts to reignite before entering a safe lockout state. This HVAC ignition module utilizes flame rectification technology for remote sensing, maintaining a minimum flame current of 1.0 µA to prevent nuisance shutdowns. The 35-705506-115 includes on-board diagnostics via a multi-code LED indicator, allowing field technicians to quickly identify faults like airflow issues or flame loss. Its polarity-insensitive design and 1/4" quick-connect terminals simplify installation for professionals servicing commercial cooking equipment, infrared burners, or unit heaters. This control is a drop-in DSI board replacement for systems requiring a 120VAC operating signal.

• Enhanced Safety: Microprocessor monitoring provides 100% shutoff in the event of flame failure or a failed 3-try sequence.
• Streamlined Troubleshooting: Integrated LED codes and dedicated flame current test pins allow for rapid diagnostic verification without breaking the circuit.
• Reliable Timing: Fixed 15-second pre-purge and 10-second TFI provide consistent, repeatable operation in diverse environmental conditions.
• Broad Compatibility: Suitable for both natural gas and LP applications across a wide operating temperature range of -40°F to 175°F.
• Durable Construction: Features a Noryl gray enclosure to protect internal components from dust and mechanical damage in demanding mechanical rooms.

What is the reset procedure after a lockout occurs?
Lockout on the Fenwal 35-705506-115 can be reset by cycling the thermostat or the 120V power supply off for a minimum of 5 seconds. This clears the microprocessor's internal fault memory and initiates a fresh ignition sequence.

How do I measure the flame signal on this board?
Use a multimeter set to the DC microamp (µA) scale. Connect your leads to the FC+ and FC- test pins while the burner is firing. A healthy signal should read 1.0 µA or higher; if the reading is negative, reverse your leads.

Can this control be used for local sensing at the igniter?
No, this specific dash-number (115) is configured for remote sensing. Ensure you have a separate flame rod wired to the sense terminal for proper flame rectification feedback.

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.