Boilers are at the heart of any comfortable home, and Ferroli is a name trusted by many households across London. But when your Ferroli boiler displays an error code, it's natural to feel concerned. These codes are designed to alert you to a fault, ranging from something simple, such as low pressure, to more serious issues that require urgent attention.
In this guide, we'll break down common Ferroli boiler error codes, explain what they mean, and help you decide whether it's something you can check yourself or if it's time to call in the experts.
At Maintracts Services, our expert heating engineers have extensive experience with Ferroli boilers, offering a full range of services, from installation and servicing to fault diagnosis and prompt, professional repairs across London. As Gas Safe-registered engineers, we're ready to help you decode error messages and get your heating and hot water working safely and efficiently.
Call us now on 020 8131 9985; our friendly team is available 24/7. You can also book online for fast assistance.
Don't let a boiler error leave you in the cold; count on Maintracts Services for rapid, reliable Ferroli boiler repairs across London.
What Are Ferroli Boiler Error Codes?
Ferroli boiler error codes are designed to help you (and your engineer) identify and diagnose issues with your boiler quickly. These codes appear on your boiler's display panel when a fault is detected, ranging from minor issues such as low water pressure (F37) to more serious concerns, including ignition failure (A01) or an air pressure switch error (F05).
Understanding what these codes mean can save valuable time, help you take simple steps like checking water pressure, and avoid unnecessary disruption to your heating and hot water. Some faults can be resolved with a reset or basic check, while others may require the expertise of a qualified gas-safe engineer.
If you're unsure what an error code means or your boiler isn't working properly, don't take risks; contact the Maintracts Services team. We're ready to assist with reliable Ferroli boiler repair in London.
Also Read: Glow-Worm Boiler Error Codes
Common Ferroli Error Codes And Quick Fixes
1. F37 – Low System Pressure
Cause: Insufficient water in the system. It could follow radiator bleeding or a small leak.
What to try:
- Locate the filling loop (silver braided hose).
- Open valves gradually until pressure reads 1.0–1.5 bar.
- Close valves and reset the boiler.
If pressure drops again, an engineer should check for leaks.
2. A01 – Ignition Failure
Cause: No gas, low pressure, or faulty ignition part.
What to try:
- Check if other gas appliances (such as a hob) work.
- Reset boiler.
- Still faulty? Call a Gas-safe engineer to inspect the gas supply and ignition.
3. F05 – Air Pressure Switch Fault
Cause: Blocked flue or faulty fan.
What to try:
- Check the external flue for blockages (e.g. debris, ice).
- If clear, an engineer needs to test the fan and switch.
4. A06 – No Flame After Ignition
Cause: Gas pressure issue, blocked condensate pipe, or sensor fault.
What to try:
- In winter, check for frozen condensate pipe; thaw gently with warm water.
- Persistent? Call an engineer for gas supply & burner check.
5. F34 – Low Voltage
Cause: Mains voltage too low (under 170V).
What to try:
- Check other appliances. If the issue is widespread, contact your electricity provider.
Pro Tip: Can't see your boiler's error code here? Scroll down to our complete Ferroli error code table for more codes, meanings, and fixes.
Also Read: Ideal Logic Boiler Fault Codes
Ferroli Boiler Error Codes By Model
Different Ferroli models show different codes. Here's a quick guide:
1. Ferroli BlueHelix Tech
- F37: Low system pressure
- A01: Ignition failure
- A06: No flame detected
- F34: Low voltage
2. Ferroli Modena HE Combi/System
- A02: Flame detected when burner off
- F07: Flue gas temperature too high
- F35: Irregular mains frequency
3. Ferroli Optimax HE Plus
- A16: Gas valve fault
- F43: Exchanger protection triggered
For a complete list of error codes, check out our Ferroli boiler error code table below.
Complete Ferroli Error Code List & Fixes
| Code | Meaning | Recommended Action |
| A01 | Ignition failure | Check the gas, reset the boiler, and call the engineer if it persists |
| A02 | Flame detected with the burner off | Reset; may need PCB or electrode check |
| A03 | Heating sensor fault (airlock/lack of circulation) | Bleed radiators, check pump |
| F04 | Card parameter error | Reset, may need reprogramming |
| F05 | Air pressure switch fault/flue issue | Check the flue, call the engineer |
| A06 | No flame after ignition | Check condensate, call the engineer |
| F07 | High flue gas temperature | Engineer inspection required |
| A09 | Gas valve or wiring fault | Call engineer |
| F10 | Flow sensor short/disconnected | Call engineer |
| F11 | Return temp sensor fault | Call engineer |
| A15 | Frequent F05 faults | The air pressure switch needs checking |
| A16 | Gas valve fault | Call engineer |
| A23 | Card parameter problem | Reset check control board |
| A24 | Card parameter problem | Reset, software check |
| F34 | Low mains voltage | Check supply, contact electricity provider |
| F35 | Mains frequency issue | Contact electricity provider |
| F37 | Low water pressure | Top up system, call if recurring |
| F39 | External probe error | Engineer check |
| F43 | Heat exchanger protection | Bleed system, call if persists |
| F50 | Internal controller error | Reset, may need replacement |
| F51 | Internal controller error | Reset, may need replacement |
| F12 | DHW sensor fault | Call engineer |
| F13 | Flue probe fault | Clean the flue, call the engineer |
| F14 | Flow sensor error | Check/replace sensor |
| F15 | Fan fault | Call engineer |
| A41 | Flow sensor disconnected | Check connection |
| A42 | Flow sensor damaged | Replace sensor |
| A50 | Gas valve fault | Call engineer |
Important: If your boiler is leaking gas, making loud noises, or frequently shutting down, stop using it and call a Gas Safe registered engineer immediately. Maintracts Services provides trusted Ferroli boiler repairs across London. Call 020 8131 9985 for expert help.
Also Read: Baxi Boiler Error Codes
Frequently Asked Questions About Ferroli Boiler Error Codes
What does error code A01 mean on a Ferroli boiler?
Error code A01 typically means there's an ignition failure. This could be due to a lack of gas supply, a faulty ignition electrode, or low gas pressure.
What causes ignition failure on a Ferroli boiler?
Ignition failure is typically caused by a lack of fuel, low fuel pressure, a faulty ignition electrode, or issues with the fuel valve or power control board (PCB). Sometimes, a blocked flue or condensate pipe can contribute.
What should I do if my Ferroli boiler keeps locking out?
Try resetting the boiler following the manufacturer's instructions. If it continues to lock out, it's best to contact a gas-safe engineer to diagnose the underlying issue safely.
How do I reset my Ferroli boiler after a fault code?
Look for the reset button on your boiler's control panel. Hold it down for about 5 seconds until the boiler attempts to restart. Always refer to your boiler manual for model-specific guidance.
Can I fix a Ferroli boiler error code myself, or should I call an engineer?
You can handle simple issues, such as topping up low pressure or thawing a frozen condensate pipe. However, for any gas-related, electrical, or persistent faults, you should always call a gas-safe engineer.
Why is my Ferroli boiler not heating water or radiators?
Common causes include low system pressure, airlocks, faulty pumps, or a broken diverter valve. It may also be related to a specific fault code; check your display and manual for more information.
How do I check the water pressure on a Ferroli boiler?
Find the pressure gauge on the front panel of your boiler. A healthy system pressure is typically between 1.0 and 1.5 bar when cold. If it's low, you may need to repressurise using the filling loop.
Are Ferroli boiler error codes the same for all models?
No! While many codes are shared across models, some are specific to certain ranges (like BlueHelix, Modena, or Optimax). Always refer to your manual or a trusted resource for your specific model.
Do I need a gas-safe engineer to repair my Ferroli boiler?
Yes! For all gas-related repairs, UK law requires that you use a Gas Safe registered engineer. It's essential for your safety and to comply with regulations.
How often should a Ferroli boiler be serviced to avoid faults?
You should service your Ferroli boiler annually. Regular servicing helps prevent faults, ensures safe operation, and maintains the validity of your warranty.
Choose Maintracts Services For Trusted Ferroli Boiler Repairs
If your Ferroli boiler is displaying error codes or not functioning properly, don't wait, our expert team is ready to assist. Maintracts Services has been supporting homeowners across London since 1974, delivering dependable boiler repairs, servicing, and emergency solutions 24/7. Here's why you depend on us:
- Local Gas Safe engineers with decades of experience
- Same-day boiler servicing is available wherever possible
- Honest pricing. No hidden extras
- Trusted by London households for over 50 years
Contact us on 020 8131 9985 to speak directly with a qualified professional and restore your boiler's performance today.