What to do
- Reset the boiler
Press the restart button.
When to call a Gas Safe engineer
If it happens again, contact Ideal quoting L6. Ideal says it needs an engineer visit.
A repair visit will usually check the gas supply, the ignition electrode and the flame sensor.
Before you book
- Note the model and serial number. They're on a label on the data badge, usually under the boiler or behind the front cover.
- Write down the exact code, and what the appliance was doing when it appeared.
- Check whether it's still under warranty. If it is, the repair may cost you nothing.
Checked against
Last reviewed September 2026. Manufacturers update their pages, and your manual is the final word.