Ignition transformers

An ignition transformer steps mains voltage up to the high voltage needed to produce the spark arc at the burner electrodes. It sits between the burner control unit and the electrode assembly, firing on demand during the ignition sequence and cutting out once the flame is established. The transformer is a safety-critical component: a weakened unit can cause ignition lockout, delayed light-off or nuisance trips even when the rest of the combustion circuit is in good order.

Selecting the correct replacement means matching primary voltage and frequency, secondary open-circuit voltage and ignition current, and the electrode connection type — single or twin output, and whether the connectors are 4 mm plug, spade or screw terminal. Physical dimensions and mounting pattern matter too, since the cabinet clearances on many boilers leave little room. If you have the original order number — from Brahma, Fida, Honeywell, ACV or any other maker represented here — use it directly in the search; cross-references to equivalent parts from other manufacturers are supported.