Weil McLain 591-391-798 Cable

The Weil McLain 591-391-798 is a critical OEM ignition cable designed for high-performance spark delivery in commercial and residential boiler systems. This 36-inch HVAC replacement part is engineered with a straight boot configuration to ensure a secure, low-resistance connection to the Q179C pilot burner. Built using AWG 14 wire and a high-temperature XLPE 105 jacket, this lead is specifically rated to withstand the intense thermal environment of the combustion chamber without insulation breakdown or signal degradation.

For technicians servicing Weil McLain EG, EGH, LGB, and MGB model boilers, this cable is the specified match for sizes 6-12 and 13-23. Utilizing genuine Weil McLain parts ensures the ignition system maintains the precise timing and voltage required to prevent delayed ignition or nuisance fault codes. The straight boot design facilitates easy routing through tight cabinet spaces, providing a robust path for the high-voltage spark necessary for reliable burner sequencing and consistent flame proofing.

• OEM Compatibility: Exact replacement for Weil McLain 591-391-798, ensuring proper fitment on Q179C pilot assemblies.
• High-Heat Resilience: Features a durable XLPE 105 insulation jacket that prevents arcing and maintains dielectric strength in high-temperature zones.
• Optimized Conductivity: AWG 14 gauge wire provides stable electrical transfer for intermittent pilot ignition.
• Versatile Application: Standard 36-inch length allows for flexible routing across multiple EG, EGH, LGB, and MGB series boiler sizes.

Is this cable compatible with secondary flame sensors?
This specific part is an igniter cable designed for the pilot assembly. While some systems use similar leads for sensing, always verify against the manufacturer’s wiring schematic for the specific LGB or MGB series you are servicing.

Can I use this for a hot surface ignition (HSI) system?
No, this lead is engineered for spark-to-pilot ignition systems. HSI systems typically require different connector interfaces and wire ratings tailored to the silicon carbide or nitride igniters.

What are the signs of a failing ignition cable?
Look for carbon tracking, visible cracks in the XLPE jacket, or brittle insulation near the boot. These issues often lead to intermittent spark failure or grounding, causing the boiler to cycle without establishing a flame.

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.