Burner Ignition Electrode Set

Function

The correct electrode tip gap — typically 3.0–4.0 mm (0.12–0.16 in) — and the tip-to-nozzle axial and radial positioning are critical to reliable light-off. Too wide a gap causes spark failure at the transformer's output voltage; too narrow risks contact with the nozzle and a dead short. Carbonised or eroded electrode tips generate a weak, diffuse spark that ignites unreliably, leading to repeated lockouts and fuel accumulation in the combustion chamber. Fresh electrodes at the correct gap setting ensure first-attempt ignition, minimising warm-up time and the cumulative fuel waste from failed start sequences.

Construction & quality

Electrode rod: Inconel or high-nickel alloy, 4–5 mm diameter, tip machined to a defined point geometry for arc concentration. Insulator: glazed alumina ceramic, 95% purity minimum, rated to 1,000 °C (1,832 °F) surface temperature and 25 kV/cm dielectric strength to prevent high-voltage tracking to the bracket. HV cable connection: push-on 4 mm silicone insulating boot rated to 8 kV. Bracket: cold-formed 304 stainless steel with an adjustment slot for precise tip-to-nozzle distance. Supplied as a factory-gapped matched pair.

When to replace

• Burner fails to light on first or second attempt despite normal fuel pressure and flow
• Ignition controller goes to safety lockout — indicating repeated ignition failure sequences
• Visible carbon deposits on electrode tips or across the ceramic insulator surface
• Ceramic insulator cracked or chipped — high-voltage tracking to the metal bracket occurs
• Electrode tip eroded to a blunt stub with a measured gap exceeding 5 mm