Ferroli Boiler Repairs London

Ferroli Boiler Repair Help Centre

Common Ferroli faults, fault codes, safe checks, and when to call a Gas Safe engineer.

Jump to: Fault Codes · A01 Fault · Pressure · Frozen Condensate · Repair or Replace

Quick Checks Before You Call Anyone

These take 60 seconds and solve a surprising number of lockouts:

1. Check the pressure gauge: If below 1 bar, top up (see guide below). More detail in our complete pressure guide.
2. Note the fault code: Ferroli displays show A or F codes like A01, A03, F04. Write it down before calling.
3. Check your fuse box: Boilers need electricity; a tripped switch is an easy fix.
4. Check thermostat and timer: Settings can change after clock changes or dead batteries.
5. Freezing weather? The condensate pipe may be frozen (see winter section below).
6. Reset once only: Press the reset button on the front panel, wait 60 seconds. If it locks out again, stop and call an engineer.

Ferroli Fault Codes

Note: Ferroli uses both A codes (lockouts requiring reset) and F codes (faults) depending on model. If unsure, call us and we will help you identify your specific code.

A01: Ignition Failure

What is happening: The boiler is trying to ignite but cannot establish a flame after multiple attempts. This is the most common Ferroli fault code.

Common causes: Frozen condensate pipe (winter), gas supply interruption, faulty ignition electrode or lead, blocked or damaged flue, gas valve fault.

What to try: Check if your gas hob or other gas appliances work. In freezing weather, check the condensate pipe for ice. If gas supply is fine but boiler will not ignite, call an engineer.

Note: On older Ferroli Domicompact and Domicondens models, A01 often indicates worn ignition electrodes or leads. These are common repair items.

A03 / F04: Overheat Lockout

What is happening: The boiler detected excessive temperature and shut down for safety.

Common causes: Restricted circulation, pump failure, limescale in heat exchanger, system sludge, faulty thermistor.

What to try: Nothing user serviceable. Do not repeatedly reset. Call a Gas Safe engineer. If circulation or sludge is the cause, a power flush may be recommended.

A06 / F37: Low Water Pressure

What is happening: System pressure has dropped below the minimum operating level.

Common causes: Small leak in system, recently bled radiators, pressure relief valve discharge, expansion vessel needs recharging.

What to try: Top up pressure using the filling loop (see below). If pressure drops again within days, there may be a leak. Read our pressure guide for step by step instructions.

How to Top Up Pressure (Ferroli)

If you are not comfortable using the filling loop, stop and call a Gas Safe engineer.

1. Locate the filling loop (usually underneath the boiler, a braided silver hose with one or two valves).
2. Ensure the boiler is off and cool.
3. Open the valves slowly, a quarter turn at a time.
4. Watch the pressure gauge rise to between 1.0 and 1.5 bar.
5. Close both valves fully.
6. Switch the boiler back on.

Do not exceed 2.0 bar. If you overfill, stop and call an engineer.

If you need to top up frequently (more than once a month), there is likely a leak. Call us for a diagnosis.

Frozen Condensate Pipe (Winter)

In freezing weather, a frozen condensate pipe is one of the most common causes behind A01 and F34 lockouts on Ferroli boilers. This is often safe to resolve with the steps below. If you are unsure, or the boiler will not restart, call an engineer.

Signs: Boiler locked out with A01 or F34, freezing temperatures outside, gurgling sound when boiler tries to start.

What to do:

1. Locate the condensate pipe (white or grey plastic pipe exiting to an outside drain).
2. Pour warm water (not boiling) over the frozen section.
3. Reset the boiler once thawed.

Full instructions: Frozen condensate pipe guide.

If it keeps happening, we can reroute the pipe internally or add insulation to prevent future freezing.

Why These Faults Are Common in London Homes

Hard water, older pipework, and winter weather make certain faults more likely in London properties:

• A01 ignition failures: Frozen condensate pipes during cold snaps are a frequent cause. Older Ferroli models also have ignition components that wear over time.
• A03/F04 overheat lockouts: London’s hard water causes sludge and limescale buildup, restricting flow and triggering overheat protection.
• Pressure fluctuations: Older London properties with microbore pipework or poorly balanced systems experience more A06/F37 low pressure faults.
• Heat exchanger scaling: Ferroli heat exchangers can scale faster in hard water areas, causing kettling and reduced efficiency.

Ferroli Models We Repair

We repair all Ferroli gas boiler models including:

• Modena: Current combi range
• Bluehelix: Premium condensing range
• Optimax: Popular combi and system range
• Torino: Compact combi models
• Domicondens: Established condensing range (now discontinued but widely installed)
• Domicompact: Older combi range, parts availability varies
• Domina: Older range, some parts constraints

Ferroli is an Italian manufacturer. We have good supplier relationships and can source parts, though some older model parts may take longer.

Common Ferroli Problems

Ignition failures (A01): The most common Ferroli repair. Often caused by worn electrodes, faulty spark generator, or gas valve issues on older Domicompact models.

Fan faults (F05): Fan not running at correct speed or failing to prove to the PCB. Common on older models.

Diverter valve sticking: Hot water works but radiators stay cold, or vice versa. Common on models over 8 years old.

PCB failure: Random lockouts, display glitches, or complete failure. Ferroli PCBs can be harder to source for older models.

Heat exchanger blockage: Kettling noises, overheating (A03/F04), reduced efficiency. Ferroli heat exchangers can be affected by limescale. See our guide to boiler noises.

Repair or Replace?

Ferroli boilers typically last 10 to 15 years with proper maintenance. If yours is approaching that age and needs a major repair (heat exchanger, PCB), replacement may be more cost effective.

Older models like the Domicompact and early Domicondens are now reaching end of life with limited parts availability. If you have one of these and it needs a major repair, replacement is often the only practical option.

We give honest advice either way. Read more: Repair or replace? An engineer’s guide.

If you decide on a new boiler: New boiler installation.

Ferroli Servicing

Annual servicing keeps your Ferroli running efficiently and maintains your warranty. We service all Ferroli models and provide a full report after each visit.

We recommend servicing in late summer or early autumn, before the heating season. Book your boiler service.

Renting? Landlords: Check This

Tenants: Your landlord is usually responsible for boiler repairs. Contact them first and keep written records, especially if you have no heating or hot water.

Landlords: Stay compliant with our Gas Safety Certificate (CP12) service. See our full London landlord checklist covering gas safety, EPCs, and maintenance requirements.

London Wide Coverage

We repair Ferroli boilers across all London boroughs including North, South, East, West, and Central London. Our engineers are based throughout the city for fast response times.

See our full London coverage area or find your local page:

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