Boiler
F10
The F10 error code on a Ferroli boiler signals a loss of flame — the boiler has tried to ignite but the burner either failed to light or the flame cut out unexpectedly. This is a lockout fault that stops the boiler running, so your heating and hot water will be off until it’s resolved.
What does this error mean?
F10 means the boiler’s control board detected that no flame was established (or was lost) during a burner cycle. The boiler attempts ignition, the ionisation sensor checks for a stable flame, and if it doesn’t detect one within the set time window, it locks out and displays F10. This is a safety shutdown — the boiler is protecting your home from unburned gas building up.
Est. repair cost
£80–£180 for Gas Safe engineer repair (parts + labour); condensate thaw is free DIY
🔍 Likely causes
🛠️ Step-by-step fix
Check your gas supply first: turn on a gas hob or cooker to confirm gas is reaching your home. If there’s no gas at other appliances, contact your gas supplier — do not attempt to reset the boiler.
Reset the boiler: press and hold the reset button (usually marked with a flame or ‘R’ icon) for 3–5 seconds. Allow the boiler a full ignition cycle — this takes up to 60 seconds. If it fires and stays on, monitor it over the next few hours.
In cold weather, check the condensate pipe: locate the white plastic pipe that exits your boiler and runs outside. If it’s frozen, thaw it carefully with warm (not boiling) water and reset the boiler afterwards.
Check your boiler pressure gauge: it should read between 1 and 1.5 bar when the system is cold. If it’s below 0.5 bar, top up via the filling loop (consult your boiler manual for the correct procedure for your Ferroli model).
If the fault returns immediately or within a short period after resetting, stop here — do not keep resetting repeatedly. Repeated failed ignition attempts can be unsafe and will not resolve the underlying fault.
All further investigation — including checking the gas valve, ionisation sensor, electrodes, or gas pressure at the meter — must be carried out by a Gas Safe registered engineer. These are not DIY tasks.
📞 When to call a professional
Call a Gas Safe registered engineer if the F10 error returns after one reset attempt, if you smell gas at any point, or if the boiler is making unusual sounds during the ignition attempt. Tell the engineer the boiler is displaying F10, that it’s a flame failure lockout, and how many times it has locked out — this helps them diagnose the fault faster.
⚖️ Repair or replace?
Most F10 faults are resolved by replacing the ionisation sensor or ignition electrode, both of which are relatively inexpensive parts — expect to pay £80–£180 for a Gas Safe engineer call-out including parts and labour. If your Ferroli boiler is over 10–12 years old and this is not the first fault, the repair cost may exceed the value of keeping it running; a new A-rated combi boiler typically costs £1,800–£2,800 installed in the UK. For boilers under 8 years old in otherwise good condition, repair is almost always the right call.