Fenwal 35-725917-000 Module

The Fenwal 35-725917-000 Module is a professional-grade 120V Direct Spark Ignition (DSI) control engineered for high-demand heating applications. This potted ignition module is specifically designed to provide robust protection in washdown or high-vibration environments, ensuring circuit integrity where open-board controls might fail. Operating on 120V AC, it manages gas valve sequences for natural gas, propane, and manufactured gas systems with high precision. The 35-72 series provides versatile configuration with a multi-pin connector for streamlined field installation and reliable flame sense monitoring (1 mA minimum). Built to withstand extreme mechanical rooms, the unit maintains a steady temperature range of -40°F to 175°F. Technicians can rely on this Fenwal DSI control for consistent timing sequences, featuring options for single or multi-trial ignition and various trial-for-ignition (TFI) timings to match specific OEM requirements and ensure safe burner light-off every cycle.

Key Technical Benefits

• Environmental Resilience: The potted enclosure prevents moisture ingress and stabilizes components against mechanical shock and vibration.
• Universal Fuel Compatibility: Fully rated for use with LP, natural, and manufactured gases, making it a versatile stock item for service vans.
• Simplified Integration: Features a multi-pin connector that reduces wiring errors and speeds up the replacement process in the field.
• Advanced Safety Logic: Integrated thermostat/power-off reset and microprocessor-based timing provide repeatable and safe ignition sequences.
• Flexible Flame Sensing: Supports both single spark and sense or remote sense configurations to accommodate various electrode setups.

Common Questions for HVACR Contractors

What is the difference between this potted module and an open-board version?
The 35-725917-000 is potted with a specialized epoxy resin. This is critical for HVACR equipment located in high-moisture areas or industrial environments where vibration could lead to lead fatigue or short circuits on an open board.

How do I reset the module if it hits a lockout condition?
Lockout reset is achieved via thermostat/power-off reset. Simply cycle the 120V power or the thermostat call for heat to clear the internal logic and initiate a new ignition sequence.

Can this replace a module with a different TFI (Trial for Ignition) time?
You must match the ignition timing (4, 7, 10, or 15 seconds) to the original appliance specifications. Using a module with a longer TFI than specified can lead to unsafe gas accumulation during the ignition trial.

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.