Fenwal 35-705501-005 Control

For veteran technicians and contractors requiring a dependable 120VAC solution, the Fenwal 35-705501-005 is a field-proven Direct Spark Ignition (DSI) control designed for gas-fired HVAC systems, commercial boilers, and infrared heaters. This microprocessor-based ignition module delivers high-precision timing without the delay of a pre-purge cycle (NoPP), initiating a 10-second Trial for Ignition (TFI) immediately upon a call for heat. As a single-try ignition control, it simplifies troubleshooting and ensures consistent startup sequences in demanding environments. Featuring DETECT-A-FLAME technology, the 35-705501-005 provides reliable flame sensing and safe-start component checks every cycle. The unit includes on-board diagnostics with a multi-status LED to pinpoint faults, such as ignition lockout or low flame signal, significantly reducing diagnostic time on the job site. Built for durability, this Fenwal 35-70 series control is compatible with both natural gas and LP applications, offering a versatile 120V replacement for legacy ignition boards.

Key Benefits

• Zero Pre-Purge (NoPP): Optimized for systems requiring instantaneous ignition without an induction motor delay.
• Enhanced Diagnostics: Integrated system diagnostic LED provides clear flash codes for rapid troubleshooting.
• Flame Sensing Accuracy: Utilizes remote flame sensing or local spark/sense with flame current test points for precise signal measurement.
• Robust Design: Rated for operating temperatures from -40°F to +160°F, ensuring performance in unconditioned spaces.
• Universal Fuel Compatibility: Engineered for Direct Spark Ignition across natural, manufactured, and liquefied petroleum gases.

Common Questions

What does 'NoPP' mean for my installation?
It indicates 'No Pre-Purge.' The control will energize the gas valve and spark immediately when 120V is applied to the L1 terminal, rather than waiting for a fan or blower to cycle.

How do I measure the flame signal on this Fenwal module?
Use a DC micro-ammeter connected to the FC+ and FC- terminals. A healthy signal should read 1.0 µA DC or higher during operation.

Is the Fenwal 35-705501-005 polarity sensitive?
This specific 120VAC model features a microprocessor designed to be polarity insensitive regarding flame sensing, which helps prevent nuisance lockouts caused by reversed hot/neutral lines.

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.