An Ideal fault code tells you why the boiler has stopped or locked out. Some, such as low pressure or a frozen condensate pipe, you can safely check yourself; most others need a Gas Safe registered engineer. Find your code below. Ideal boilers show a flashing L (lockout), F (fault) or C code with a number, for example L2 or F1. Check your user manual for your exact model.
Smell gas, or a carbon monoxide alarm is sounding? Do not reset the boiler. Open windows, turn off the gas at the meter if it is safe to do so, leave the building and call the free gas emergency line on 0800 111 999. What to do →
Ideal fault codes and what to do
F1You may be able to fix this
What it means: Low pressure.
What to do: Top up the system pressure to between 1 and 1.5 bar using the filling loop, as shown in your manual.
L2 / F2You may be able to fix this
What it means: Flame loss or ignition lockout: the boiler could not light or keep its flame.
What to do: Reset the boiler. Check your gas supply, prepayment credit and that the yellow gas isolation valve is open. If the boiler gurgles while trying to fire, the condensate pipe may be blocked or frozen.
L1You may be able to fix this
What it means: Flow temperature overheat or no water flow.
What to do: Make sure all radiator valves are open and the pressure is between 1 and 1.5 bar, then reset.
L3You may be able to fix this
What it means: No water flow.
What to do: Check the pressure (1 to 1.5 bar), bleed the radiators, recheck the pressure, then reset.
L5You may be able to fix this
What it means: The boiler has been reset too many times in 15 minutes.
What to do: Turn the power off and on again. If the original fault returns, call an engineer.
L6Engineer needed
What it means: False flame lockout.
What to do: Reset once. If it persists, a Gas Safe engineer is needed.
F3Engineer needed
What it means: Fan fault.
What to do: Reset once. If it persists, a Gas Safe engineer is needed.
F4 / F5Engineer needed
What it means: Flow (F4) or return (F5) thermistor fault.
What to do: Reset once. If it persists, an engineer is needed.
F6Engineer needed
What it means: Outside sensor fault.
What to do: Reset once. If it persists, an engineer is needed.
F7Engineer needed
What it means: Low mains voltage.
What to do: Ideal advises a local electrician checks the property's electrics.
F0Engineer needed
What it means: No water flow thermistor.
What to do: Reset once. If it persists, an engineer is needed.
C0 / C2Engineer needed
What it means: Boiler control chip (BCC) activation or chip fault.
What to do: Reset once. If it persists, an engineer is needed.