28
Immergas Delayed Ignition / Combustion Instability

Boiler shows error 28, ignition attempts are noisy or delayed, sometimes with small explosions (misfires).

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Incorrect electrode position, Dirty burner, Incorrect gas pressure, Faulty gas valve modulation

How to Fix / Troubleshooting

Safety: Delayed ignition can be dangerous. Turn off the boiler and gas supply and contact a qualified gas engineer. Do not continue to reset the boiler.

  • Inspect ignition electrode: Check the electrode for correct gap and position relative to the burner. Clean or replace if worn or cracked.
  • Clean burner: Remove and clean the burner thoroughly, ensuring all ports are clear.
  • Check gas pressures (engineer): Verify inlet and burner pressures with a manometer and adjust the gas valve as per Immergas data.
  • Combustion check: Perform a flue gas analysis to ensure correct combustion. Replace the gas valve if modulation is unstable.
  • Final test: After repair, observe several ignition cycles to confirm smooth, quiet ignition without error 28.
Advertisements

Repair Difficulty

Professional Required 5/5

Required Part

Ignition Electrode
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements