Allanson 421-331 Transformer

The Allanson 421-331 Ignition Transformer is a high-performance direct replacement oil burner transformer engineered specifically for Lennox oil burners. Designed for reliability in demanding combustion environments, this unit features a 120V primary supply voltage and a robust 10,000V secondary output at 23mA. The midpoint ground configuration ensures stable arc performance and minimizes electromagnetic interference within the burner housing. Built with high-grade silicone rubber bushings and a specialized epoxy resin potting compound, the 421-331 provides superior moisture resistance and thermal dissipation for consistent oil burner electrode ignition. This transformer meets the precise electrical requirements for maintaining a stable flame signal, crucial for modern HVAC flame safety controls. Contractors can rely on this heavy-duty unit for field repairs where OEM-spec high voltage ignition is required to ensure efficient fuel atomization and combustion cycles.

• OEM Compatibility: Specifically designed as a drop-in replacement for Lennox burner ignition systems, reducing field modification time.
• High-Voltage Stability: Delivers a consistent 10kV output to ensure reliable oil furnace spark ignition even in cold starts.
• Mid-Point Grounding: Optimized electrical architecture to reduce stress on internal components and improve diagnostic accuracy.
• Durable Construction: Engineered to withstand the high ambient temperatures common in residential and light commercial oil-fired appliances.

Will this transformer replace older iron-core units?
Yes, the Allanson 421-331 is designed to replace traditional heavy iron-core Lennox transformers provided the mounting footprint and 120V primary requirements match.

What causes premature failure in these ignition units?
Consistent failure is often linked to incorrect electrode gap settings or carbon soot buildup, which forces the transformer to work harder to jump the arc; always check burner electrode settings during installation.

Is the 23mA rating sufficient for commercial applications?
The 23mA secondary current is the standard rating for most residential and light commercial oil burners, providing more than enough power for a strong, consistent ignition spark.

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.