EOGB ZT930 Transformer 240V Oil

The ZT930 is a 240V oil ignition transformer manufactured by EOGB and used across the EOGB, Honeywell and Satronic oil boiler control range. It supplies the high-voltage spark that ignites the oil and air mixture at the burner during a call for heat. The transformer is fitted as part of the burner control assembly on compatible oil-fired boilers.

• The burner runs through pre-purge but fails to establish a flame, with no spark visible at the electrodes.
• Repeated lockouts on start-up that are not resolved by cleaning or re-gapping the electrodes.
• Intermittent ignition, where the burner lights on some attempts but not others.
• A buzzing or arcing noise from the transformer body, or visible tracking and carbon marks around the terminals.
• No output at the transformer secondary when tested, despite correct 240V supply at the primary.

• Confirm the existing transformer is marked ZT930 and that the burner control assembly matches the EOGB, Honeywell or Satronic application.
• Check the supply voltage at the burner is 240V and that the transformer terminals and leads are sound before condemning the part.
• Inspect the ignition electrodes, leads and burner earth for damage, as these can mimic a failed transformer.
• Isolate the appliance electrical supply and follow the burner manufacturer's instructions for removal and refitting.