Robertshaw 790-400 Pilot Mod.

The Robertshaw 790-400 RAM-4 120V Intermittent Pilot Module is a critical gas ignition control designed for use in atmospheric heating systems and commercial cooking equipment. As a direct replacement for various 790 series ignition modules, this 120V AC unit manages the ignition sequence by providing a high-voltage spark to the pilot burner while simultaneously monitoring the flame through flame rectification technology. This module features a 15-second trial for ignition (TFI) and includes a 100% shut-off safety lockout if the pilot fails to ignite or sustain a flame. The rugged RAM-4 solid-state circuitry ensures reliable performance in high-temperature environments, making it a staple for contractors maintaining 120V intermittent pilot ignition systems. Its compact footprint and standard terminal layout allow for streamlined field installation and troubleshooting. This HVACR replacement part is engineered to interface seamlessly with existing gas valves and pilot assemblies to restore safe, automatic burner operation.

Key Benefits

• Universal 120V Compatibility: Specifically engineered for 120V AC systems, ensuring stable power delivery to the intermittent pilot assembly.
• Safety Lockout Protection: Features a 100% shut-off mechanism that terminates gas flow if the flame sense circuit is not completed within the TFI window.
• Flame Rectification Technology: Utilizes precise sensing to prevent "nuisance tripping" and ensure the main valve only opens once a stable pilot is established.
• Durable Solid-State Design: The RAM-4 architecture provides vibration resistance and thermal stability for long-term reliability in demanding enclosures.

Common Questions

How do I verify if the 790-400 is the correct replacement for my existing control?
Confirm that your system operates on a 120V AC primary circuit and requires an intermittent pilot module with a 15-second TFI. Check the terminal designations on your old module to ensure they match the Robertshaw 790-400 layout for spark, sense, and valve control.

What should I check if the module is not producing a spark?
Ensure the module is receiving 120V at the L1 terminal and that the ground connection to the burner assembly is secure. Inspect the high-voltage cable for cracks and verify the spark gap at the pilot electrode is within manufacturer specifications.

Can this module be used with LP (Liquid Propane) systems?
Yes, provided the gas valve and pilot assembly are properly rated for LP gas. The Robertshaw 790-400 manages the timing and safety logic independently of the fuel type, but the 100% lockout feature is mandatory for LP applications.

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.