Boiler shows E11; burner may shut down unexpectedly during operation.
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.
Possible Causes
How to Fix / Troubleshooting
Safety: If flame is repeatedly lost, do not continue resetting the boiler. Gas and combustion issues must be handled carefully.
- Check other gas appliances: Confirm that stoves or other gas equipment operate normally. If they also fail, contact your gas supplier.
- Inspect flame sensor wiring: With power off, ensure the flame sensor lead is tight at both the sensor and control board.
- Clean burner and sensor: If accessible, inspect the burner surface for debris or corrosion. Clean the flame sensor as described in earlier steps.
- Vent and air check: Verify that intake and exhaust vents are clear to prevent unstable combustion.
Persistent E11 indicates a combustion stability problem. A licensed technician must perform combustion analysis, verify gas pressures, and replace the gas valve, flame sensor, or control board as needed.