Over 20+ years experience with Ferroli Boilers
0203 695 3137
Boiler Repairs R Us are experienced in handling all types of Ferroli Boilers. We can also assist with all gas, condensing, combi boiler installations and upgrades. All our plumbers are Gas Safe Registered so you can be assured all our work is carried out within the required regulations. So for complete customer satisfaction call us on 0203 695 3137 to get your Ferroli Boilers repaired today!
Trusted, reliable boilers repair & install specialists.
Get pricing and book repairCommon Ferroli faults, fault codes, safe checks, and when to call a Gas Safe engineer.
We specialise in Ferroli boiler repairs across London.
Gas Safe registered engineers for safe diagnosis, repair and testing.
24/7 availability with London wide call handling and booking.
Seeing A01, F37 or F05? No heating or hot water? Tell us the fault code, model and postcode and we will advise the quickest safe next step.
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Fast triage: Ferroli model (BlueHelix, Modena, Optimax and similar), fault code, postcode, and whether other gas appliances work for ignition faults.
Smell gas? Do not touch anything. Do not use switches. Open windows, leave the property, and call the National Gas Emergency Line: 0800 111 999.
Carbon monoxide alarm sounding? Get everyone out immediately and call 999. Learn more about carbon monoxide safety.
No gas smell, no alarm? Your boiler may have locked out as a safety precaution. Try the quick checks below.
Jump to: Fault Codes · A01 Ignition · Pressure · Frozen Condensate · Repair or Replace
These take 60 seconds and solve a surprising number of lockouts:
Note: Ferroli fault codes can vary by model and generation. If your code is not listed here, call us with the exact code and model and we will advise the safest next step.
| Code | What It Means | What To Do |
|---|---|---|
| A01 | Ignition failure (no burner ignition) | Check gas supply and whether other gas appliances work. In freezing weather, check condensate pipe. If still locked out, call an engineer. |
| A06 | No flame after ignition phase | Reset once. Check if other gas appliances work and check condensate pipe in winter. If it returns, call an engineer. |
| F37 | Low system water pressure | Top up to 1.0 to 1.5 bar. If it drops again within days, call an engineer. |
| F05 | Fan or flue / air pressure switch issue | Do not attempt DIY on flues. If it returns after a reset, call an engineer for safe checks. |
| A03 | Overheat or circulation related protection (model dependent) | Do not keep resetting. If radiators are cold or noisy, call an engineer to check circulation and safety controls. |
| F34 | Low mains voltage (model dependent) | Reset once. If it continues, call an engineer to assess electrical supply stability and boiler response. |
| F35 | Mains frequency / electrical supply issue (model dependent) | Reset once. If it repeats, call an engineer. |
| F43 | Exchanger protection or poor circulation (model dependent) | Call an engineer. This often indicates circulation issues that need safe diagnosis. |
What is happening: The boiler is trying to ignite but cannot establish a stable flame.
Common causes: Gas supply interruption, frozen condensate pipe (winter), ignition components, airflow or flue related issues, gas valve or PCB related faults.
What to try: Check your gas hob or other gas appliances work. In freezing weather, check the condensate pipe for ice. Reset once only. If the boiler will not ignite, call an engineer.
What is happening: System pressure has dropped below the minimum operating level and the boiler may lock out to protect itself.
Common causes: Recently bled radiators, a small leak, pressure relief discharge, or the expansion vessel needing attention.
What to try: Top up using the filling loop and aim for 1.0 to 1.5 bar. If you need to top up frequently, there is likely a leak or a component issue. Use our pressure guide.
If you are not comfortable using the filling loop, stop and call a Gas Safe engineer.
Do not remove the boiler casing. If you cannot locate the filling loop easily, call an engineer.
Do not exceed 2.0 bar. If you overfill, stop and call an engineer.
In freezing weather, a frozen condensate pipe can cause ignition related lockouts on condensing 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: Lockout during freezing temperatures, gurgling when the boiler tries to start, repeated ignition failures such as A01 or A06.
What to do:
Full instructions: Frozen condensate pipe guide.
Hard water, older pipework, and winter weather make certain faults more likely in London properties:
We repair Ferroli boiler models including:
Ignition failures (A01, A06): Often linked to gas supply symptoms, condensate freezing, ignition components, or airflow issues that need safe testing.
Low pressure (F37): Common after bleeding radiators or due to a small system leak.
Fan and flue faults (F05): Airflow proving issues that require safe inspection by an engineer.
Circulation and overheating: Sludge, limescale, pump issues or restricted flow can trigger protection codes. A power flush may be recommended if sludge is suspected.
If your Ferroli keeps locking out and you also have cold radiators or noisy pipework, restricted circulation can contribute to overheating and recurring faults. A power flush clears debris and improves flow. Learn more about power flushing.
Ferroli boilers typically last 10 to 15 years with proper maintenance. If yours is approaching that age and needs a major repair (PCB, fan assembly, heat exchanger), replacement may be more cost effective.
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.
Annual servicing helps keep your Ferroli running safely and efficiently. We service Ferroli models and provide a clear report after each visit.
We recommend servicing in late summer or early autumn, before the heating season. Book your boiler service.
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 boiler maintenance.
We repair Ferroli boilers across all London boroughs. See our London coverage area or find your local page:
Gas Safe engineers available across London. Speak to our team for safe next steps.