What replacement criteria apply for a Beckett oil furnace transformer?

Replacement is typically justified when spark is weak or intermittent after verifying electrode condition, gap, grounding, and wiring. Frequent lockouts, delayed ignition, and audible arcing outside the electrode area indicate HV leakage or insulation breakdown. Visible cracking, carbon tracking, burnt odor, or overheating marks on the transformer housing are strong replacement signs. If measured output is below specification or fails under load conditions, replacement is recommended. Because ignition transformers are safety critical and relatively low cost compared to downtime and risk, preventative replacement is common when symptoms appear.