Boiler shows EA; ignition failure or flame lost during operation

Safety: If you smell gas, do not attempt to reset the boiler. Ventilate the area, do not use electrical switches, and contact emergency gas services.

• Check gas supply: Confirm that the gas isolation valve under the Junkers boiler is open and that other gas appliances work.
• Reset boiler: Use the reset button once. Observe whether the boiler attempts to ignite (clicking sound) and whether the burner lights briefly.
• Check flue and air intake: Ensure the flue terminal is not blocked, which can affect combustion.
• Technician tasks:
  • Inspect and clean the ignition and ionisation electrodes; check the spark gap and replace electrodes if cracked or heavily worn.
  • Clean the burner and check for blocked injector ports.
  • Measure gas inlet and burner pressure; adjust or replace the gas valve if out of specification.
  • Check the ignition transformer and wiring on the main PCB.