Ferroli A62 Fault Code: Causes, Fixes & Repair Costs
What does the Ferroli A62 fault code mean?
The A62 code signals that the boiler's control board (PCB) has lost communication with the gas valve and can no longer regulate gas flow safely. Without this communication link, the boiler refuses to fire as a precaution. A62 is a hard lockout fault — unlike 'F' prefix codes on Ferroli boilers, which may clear on their own once the underlying condition resolves, any code beginning with 'A' requires a manual reset after the fault has been diagnosed and fixed. Because this code directly involves gas-carrying components, a Gas Safe registered engineer must carry out all investigative and repair work.
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
- Damaged or disconnected wiring loom Common
The cable harness running between the PCB and the gas valve can develop breaks, loose connectors, or corrosion over time, especially in older boilers or those that have experienced water ingress. A break anywhere in this circuit prevents the two components from communicating and immediately triggers A62.
- Faulty gas valve Sometimes
If the wiring is found to be sound, the gas valve itself may be internally damaged or have failed electrically. A Gas Safe engineer will carry out continuity and resistance checks on the valve's solenoids to confirm whether the component is at fault.
- Failed PCB (control board) Sometimes
The PCB acts as the boiler's brain, and if the processor or the output circuits responsible for gas valve control have failed, the communication link will be lost. PCB faults can sometimes be triggered by power surges or prolonged damp conditions inside the boiler casing.
How to fix it
- Attempt a single manual reset DIY safe
Locate the reset button on your Ferroli boiler's control panel (usually marked with a flame or reset symbol) and hold it for a few seconds. If the boiler fires up normally, monitor it closely over the next hour. If the A62 code returns, do not continue resetting — repeated resets will not resolve an underlying electrical or component fault and may mask a developing problem.
- Check that the boiler's electrical supply is stable DIY safe
Ensure the boiler's fused spur switch is on and that no fuses or circuit breakers in your consumer unit have tripped. A momentary power interruption can occasionally cause a one-off communication error, but a genuine A62 fault will return after reset.
- Do not attempt to open the boiler casing or inspect internal wiring yourself Gas Safe engineer
The wiring loom between the PCB and gas valve is internal to the boiler and located near gas-carrying components. Inspecting or repairing it requires a Gas Safe registered engineer with the correct test equipment.
- Gas Safe engineer: test wiring loom continuity Gas Safe engineer
Using a multimeter, the engineer will check each conductor in the cable harness between the PCB and the gas valve for breaks, high resistance, or intermittent connections. A wiring repair or loom replacement is a relatively straightforward fix if the components themselves are sound.
- Gas Safe engineer: test and replace the gas valve if required Gas Safe engineer
If the wiring is confirmed intact, the engineer will electrically test the gas valve solenoids. A valve that fails these tests will need to be replaced with a manufacturer-approved part before the boiler can safely operate.
- Gas Safe engineer: test and replace the PCB if required Gas Safe engineer
Should both the wiring and the gas valve test within specification, the control board itself is the likely culprit. The engineer will verify this before ordering a replacement PCB, as this is the most costly repair route. On older Ferroli models, parts availability should be confirmed before committing to the repair.
- Call a Gas Safe registered engineer if the fault persists or you smell gas Gas Safe engineer
If your boiler locks out with A62 and does not clear after a single reset, book a Gas Safe engineer promptly. If at any point you detect a smell of gas, leave the property immediately without operating any switches, and call the National Gas Emergency Service on 0800 111 999.
Parts you may need
- Ferroli gas valve · from £120
- PCB / control board (Ferroli compatible) · from £130
- Wiring loom / cable harness · 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–£350, depending on the underlying cause.
Frequently asked questions
Can I reset the boiler myself when it shows A62?
You can try a single reset — press and hold the reset button on the control panel until the boiler attempts to restart. If A62 clears and the boiler runs normally, keep an eye on it. However, if the code comes back after one or two resets, stop resetting and call a Gas Safe engineer. Repeated resets will not fix an underlying wiring, valve, or PCB fault, and continuously attempting them is not recommended.
How much does it cost to fix a Ferroli A62 fault in the UK?
Most homeowners pay between £150 and £350 all-in, depending on what the engineer finds. A wiring repair sits at the lower end, a gas valve replacement in the middle, and a PCB replacement towards the top of that range. Parts for Ferroli boilers are generally competitively priced compared with some premium brands, though availability can be slower for older discontinued models. In rare cases where both the valve and PCB need replacing together, costs could exceed £400 — if that applies to an older boiler, it is worth getting a new-boiler quote at the same time.
Is my Ferroli boiler safe to leave while I wait for an engineer?
If the boiler has locked out and you cannot smell gas, it is generally safe to leave it off while you arrange an appointment. The boiler will not attempt to fire while in lockout. However, if you smell gas at any point, leave the property immediately, avoid operating any electrical switches, and call the National Gas Emergency Service on 0800 111 999. Do not re-enter until the property has been declared safe.
My Ferroli boiler is over 10 years old — is repair worth it for A62?
It depends on the repair cost relative to the boiler's remaining lifespan. As a rough guide, if the repair quote is approaching 30–40% of the cost of a new boiler, replacement is usually the better long-term investment, particularly if your boiler has had previous faults. A Gas Safe engineer can advise on the condition of the rest of the boiler once they have diagnosed the A62 fault, which will help you make an informed decision.