Ferroli A10 Fault Code: Causes, Fixes & Repair Costs

Common causes

• No gas supply or insufficient gas pressure Common

  The single most common reason for an ignition lockout on any Ferroli boiler is that no gas — or not enough gas — reaches the burner. This can be as simple as a prepayment meter running out of credit, the gas isolation valve being inadvertently closed, or a network supply interruption from your provider. Check whether other gas appliances in the property work normally.

• Faulty or worn ignition electrode Common

  The ignition electrode produces the spark that lights the burner. Over time the ceramic insulator cracks, the tip erodes, or carbon deposits build up, preventing a reliable spark from forming. You may hear the boiler click repeatedly without lighting, or it may light briefly and then cut out.

• Frozen or blocked condensate pipe Common

  In cold weather the condensate pipe — usually a white plastic pipe running through an external wall — can freeze solid. This causes a blockout that prevents the boiler from firing safely. This is especially likely if temperatures have dropped below zero overnight.

• Flame sensor (ionisation probe) failure Sometimes

  Even if the burner does light, a dirty or degraded flame sensor may fail to confirm the flame to the PCB. The boiler then shuts down within a second or two as a precaution. You might notice a brief burst of flame followed immediately by lockout.

• Blocked or partially obstructed flue Sometimes

  Debris such as leaves, a bird nest, or ice can partially block the flue outlet. If combustion gases cannot escape freely the boiler's safety systems prevent or abort ignition. This is more likely on horizontal terminal flues close to ground level or beneath overhangs.

• Faulty gas valve Sometimes

  The gas valve controls the flow of gas to the burner. If it sticks closed, fails to open fully, or its solenoid coil burns out, the burner cannot receive fuel and lockout follows. Gas valve faults are less common than electrode or sensor faults but do occur on older units.

• PCB (printed circuit board) fault Rare

  The PCB coordinates ignition timing, fan speed, and flame detection. A failing PCB may send incorrect signals that result in repeated lockout even when all other components are functioning correctly. This is typically a diagnosis of exclusion after other causes have been ruled out.

How to fix it

1. Check that your gas supply is working DIY safe

   Turn on a gas hob ring or another gas appliance in the property. If nothing lights and there is no gas, check your meter — a prepayment meter may need topping up, or the isolation valve at the meter may have been accidentally closed. If neighbours are also without gas, contact your gas network operator. There is nothing further you can do until supply is restored.

2. Inspect the condensate pipe if the weather is freezing DIY safe

   Locate the white plastic condensate pipe that exits through an external wall, usually ending near a drain or outside wall. If it is frozen you will often see a bulge of ice or hear a gurgling noise when the boiler tries to start. Slowly pour warm (not boiling) water along the pipe until it thaws. A hot-water bottle held against the pipe also works well. Once thawed, reset the boiler and monitor it.

3. Reset the boiler — but no more than twice DIY safe

   Find the reset button on your Ferroli boiler — it is typically marked with an 'R' or a flame symbol. Press and hold it for approximately five to ten seconds until the display changes. Allow the boiler a full minute to attempt ignition. If the fault clears and the boiler runs normally, monitor it over the next hour. If the lockout returns, attempt one more reset. Do not reset more than two or three times in quick succession — repeated forced ignition attempts without resolving the underlying fault can overheat the heat exchanger and cause expensive secondary damage.

4. Check the flue terminal for obvious blockages DIY safe

   From outside the property, visually inspect the flue outlet. Look for leaves, debris, a bird nest, or ice covering the terminal grille. If there is an obvious external blockage you can safely remove by hand or with a soft brush, do so. Do not probe inside the flue or dismantle any flue components — that requires a Gas Safe engineer.

5. Call a Gas Safe registered engineer Gas Safe engineer

   If the lockout persists after checking the gas supply, thawing the condensate pipe, and attempting a reset, the fault lies with an internal component — most likely the ignition electrode, flame sensor, gas valve, or PCB. All of these require a qualified Gas Safe registered engineer to diagnose and replace safely. Working on gas components without Gas Safe registration is illegal under UK gas safety legislation and genuinely dangerous. When you call, mention the code displayed and describe whether the boiler sparks but does not light, lights briefly and cuts out, or makes no attempt to ignite at all — this will help the engineer bring the most likely replacement parts.

Parts you may need

• Ignition electrode assembly · from £35
• Flame sensor / ionisation probe · from £25
• Gas valve · from £120
• PCB (control board) · from £150
• Condensate trap · from £18

The exact spare depends on your boiler's GC number (on the data badge). Check this against the part before buying.

Typical repair cost

Expect to pay roughly £120–£350, depending on the underlying cause.

Frequently asked questions