Ferroli F61 Fault Code: Causes, Fixes & Repair Costs
What does the Ferroli F61 fault code mean?
The F61 code (sometimes displayed as A61 on certain Ferroli models) points to an internal error on the boiler's AGC01 printed circuit board — the main control unit that manages all key functions including gas valve operation. When this fault appears, the boiler locks out completely, cutting off both heating and hot water until the root cause is identified and resolved. Because the PCB is responsible for signalling the gas valve to open and close safely, any breakdown in that communication chain triggers this lockout as a protective measure. Note that fault code behaviour can vary slightly between Ferroli model generations, so always quote your exact model number when speaking to an engineer.
General guidance only — not a substitute for professional advice, and not certified by a Gas Safe engineer. Always have your specific appliance assessed by a qualified professional. Any gas work must be carried out by a Gas Safe registered engineer. If you smell gas or suspect carbon monoxide, leave the property and call the National Gas Emergency line on 0800 111 999.
Common causes
- Faulty PCB (AGC01 control board) Common
A failed or damaged AGC01 control board is the most direct cause of this fault code. Internal component failures, short circuits, or moisture ingress on the board can all prevent it from communicating correctly with the gas valve, triggering the lockout. As the PCB is expensive, engineers will typically rule out other causes first before condemning the board.
- Wiring or connector faults Common
Vibration from the pump or fan can gradually loosen wiring connections to the PCB or gas valve over time. Water leaks inside the boiler casing can also corrode terminals. A loose or corroded connector can mimic a full PCB failure, so this is usually one of the first things an engineer will inspect.
- Faulty or seized gas valve Sometimes
The gas valve controls gas flow to the burner. If the valve's solenoid coils fail, the valve seizes, or it loses its expected electrical resistance, the PCB detects the mismatch and raises the F61 error. Gas valves on Ferroli boilers are generally replaced rather than repaired when found to be defective.
- Gas supply interruption Sometimes
If there is no gas — or insufficient gas pressure — reaching the boiler, the PCB may log a communication-style fault. Check whether other gas appliances in the property (hob, gas fire) are working normally. If they are not, the issue is with your gas supply rather than the boiler itself; contact your gas supplier.
- Low system water pressure Rare
A system pressure below the recommended 1.0–1.5 bar range can occasionally cause the boiler's controls to behave unexpectedly and display misleading fault codes. Check the pressure gauge on the boiler front panel before assuming an electronic fault.
How to fix it
- Check other gas appliances in the property DIY safe
Turn on a gas hob ring or gas fire to confirm gas is reaching the property. If other appliances are also not working, you have a supply interruption — contact your gas network provider rather than attempting a boiler reset.
- Check the boiler system pressure DIY safe
Look at the pressure gauge on the boiler. It should sit between 1.0 and 1.5 bar when the system is cold. If it reads below 1.0 bar, top it up using the filling loop (usually a flexible braided hose or a built-in valve beneath the boiler). Add water slowly until the gauge reaches around 1.2–1.3 bar, then close the filling loop.
- Bleed radiators if pressure keeps dropping DIY safe
If you notice the pressure gauge drops repeatedly, trapped air in the radiators may be the cause. Use a radiator bleed key to release air from each radiator, starting on the ground floor. Re-check and top up pressure to 1.2 bar afterwards.
- Reset the boiler once DIY safe
Locate the reset button on the boiler fascia — on most Ferroli models it is clearly labelled. Press and hold it for approximately 10 seconds. If the boiler fires up successfully and the F61 code clears, monitor it closely over the next few hours. Do not reset more than two or three times in total; repeated resetting without fixing the underlying cause can cause further issues and may not be safe.
- If the fault returns, stop resetting and call a Gas Safe registered engineer Gas Safe engineer
A returning F61 means the underlying fault — whether a PCB fault, wiring issue, or gas valve problem — has not been resolved. An engineer will carry out a full inspection: checking wiring harnesses and connectors for damage, testing the gas valve solenoids for correct resistance, and assessing the PCB for visible damage or component failure. Parts will be replaced as necessary. Do not attempt to open the boiler casing, touch the gas valve, or interfere with the PCB yourself — this work must be performed by a Gas Safe registered engineer.
Parts you may need
- Ferroli AGC01 PCB (control board) · from £280
- Ferroli gas valve · from £175
- Wiring harness / connector loom · from £45
- Gas valve solenoid coil · from £35
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 £150–£450, depending on the underlying cause.
Frequently asked questions
Can I fix an F61 fault myself on a Ferroli boiler?
The safe DIY checks are limited to confirming your gas supply is on, topping up system pressure to around 1.2 bar, and attempting a single reset. Beyond that, the F61 involves the PCB and gas valve — components that must only be worked on by a Gas Safe registered engineer. Attempting DIY repairs on gas components is illegal under UK Gas Safety Regulations and potentially dangerous.
How much does it cost to repair a Ferroli F61 fault in the UK?
Most F61 repairs fall in the range of £150–£450 depending on what has failed. A wiring or connector fix at the lower end, a gas valve replacement typically £250–£380 including labour, and a PCB replacement at the higher end. If your boiler is over 10 years old or has a poor service history, an engineer may advise that replacement is more cost-effective than a PCB repair, which can push costs toward £500–£600 or more — worth discussing before committing to parts.
Why does my Ferroli boiler keep showing F61 after I reset it?
A fault code that returns after resetting means the underlying cause has not been fixed — the reset simply clears the lockout temporarily. Common repeat offenders are intermittent wiring faults, a gas valve that is beginning to fail, or a PCB with a developing fault. Each additional reset without a repair risks further damage. Book a Gas Safe engineer to diagnose and fix the root cause.
Is F61 the same as A61 on a Ferroli boiler?
Yes, on most Ferroli models F61 and A61 refer to the same AGC01 PCB internal error. The letter prefix can differ depending on the model generation and display type — F typically denotes a fault lockout on newer displays, while A (alarm) appears on some older or different-range models. If you are unsure whether your code matches this page, quote your exact model number and the code you see to your engineer.