Faults and error codes of Ferroli boilers: deciphering, causes, ways of elimination

Boilers are essential to keeping our homes warm and comfortable, particularly in the winter. But just like any other appliance, they can occasionally have problems that leave us baffled. You may have noticed error codes flashing on your Ferroli boiler’s display, which indicates that something isn’t quite right. You can avoid a cold house, wasted time, and money by being aware of these error codes, what they mean, and how to resolve them.

Ferroli boilers are renowned for their dependability and efficiency, but even the best appliances occasionally break down. Your boiler is essentially attempting to communicate with you when it displays an error code, signaling that it has found an issue. At first, decoding these error codes might seem like decoding a secret language, but with a little help, you can troubleshoot the problem and restore your boiler’s functionality.

On a Ferroli boiler, each error code denotes a distinct issue or flaw in the system. These error codes offer helpful hints as to what’s causing the problem, from ignition problems to sensor malfunctions. Homeowners can determine whether a problem is something they can solve on their own or if they need professional help by knowing the meaning behind these codes and taking the appropriate action.

Ferroli boiler malfunctions can have a variety of causes, from straightforward ones like low water pressure or airlocks to more complicated ones like defective parts or electrical problems. Occasionally, the fix could be as simple as turning the boiler back on or changing the settings. In other situations, though, troubleshooting might entail looking over different boiler components or enlisting the assistance of a skilled technician.

The most common errors

Depending on the model, gas boiler Ferroli can simultaneously produce a number of interconnected errors. In this situation, a technician should be contacted and a thorough diagnosis should be made. Resetting the equipment doesn’t always solve the issue; sometimes, individual parts need to be changed.


The impossibility of ignition is the root of the problem.

This is due to a few factors:

  • No gas supply – the tap valve on the pipe is closed, or there is no gas in the system itself.
  • Piping is bled – often happens when the heating system is first started up.
  • Faulty gas valve – factory defect or worn-out element, which causes emergency shutdown of the boiler.
  • The ignition power is insufficient – does not correspond to the values stipulated in the specifications.
  • Incorrect angle between the electrode and the burner – does not allow ignition.
  • Electrode is covered with soot and grime – no proper conductivity.
  • Nozzles are not set correctly.
  • Too low pressure (less than 20 mbar) – ignition process is blocked.
  • Problems with the central control board – caused by power surges in the network.

The inaccuracy is indicated by the inability to ignite the boiler completely or by the boiler extinguishing on its own after five to seven seconds. You can only verify that the gas supply tap is open or that there is gas in the system on your own. Only a master can take further action; only he or she will examine the boiler and diagnose any potential issues.

The following will be repaired:

  • Restore the correct pressure in the system and adjust the nozzles according to the manufacturer"s requirements.
  • Electrode pair replacement or their cleaning from strong contamination.
  • Replace the gas valve, as in most cases it cannot be repaired.
  • Setting the correct angle between the electrode and the burner.

If the board is the issue, a new one will be installed. The boiler is restarted following the repair, and the outcome is assessed.


When the burner is off, a false signal is created that suggests there is a flame. Reignition is not possible and boiler operation is blocked. A central control board malfunction is a common cause. Incorrectly set angles between the burner and the electrode, as well as a broken contact in the wire connecting the board and the electrode, are examples of indirect causes.

Since opening the gas equipment and inspecting every component of the combustion chamber is required, it is not possible to remove the error on its own. First, the board is examined. A new one is installed if there is even the remotest possibility of a malfunction.


When the water in the circuit reaches a temperature above 90°C, the boiler overheats and an error occurs. The temperature sensor for the Ferroli Domiproject C24 model activates when the temperature rises above 105°C.

This happens in the following situations:

  • Failure of the temperature sensor itself – broken contacts, short circuit, oxidation at the connection point.
  • Voltage instability in the power supply – it is lower or higher than normal, and there is no stabilizer.
  • Pump malfunction – it stops pumping the coolant, which leads to overheating of the boiler, and the batteries are cold.
  • The system is over inflated – the air warms up faster than the water.
  • Low pressure in the heating system – there are leaks or the make-up valve is not closed.
  • Problems with the expansion tank, including blowing out.

Only three tasks are doable by yourself: verify that the pump is operating correctly, empty the batteries, and adjust the mains voltage.

An additional task is completed by a craftsman:

  1. Removing and checking the serviceability of the temperature sensor.
  2. Control of the pump, its replacement if there is a malfunction.
  3. Evaluate the operation of the expansion tank, purge and evacuate it with the help of the pump.
  4. Search for leaks and other causes of very low pressure in the heating system.

It is necessary to allow the boiler to cool before beginning the inspection.

You have to wait for the water in the system to cool down before bleeding the radiators. If not, there’s a chance you could burn yourself while doing the surgery.


After a while, the flame goes out and the code appears.

Possible causes include:

  • Insufficient pressure in the gas supply system – gas may be shut off.
  • The nozzles are not adjusted and the gas pressure is insufficient.
  • Soot and soot on the electrode, its burning out.
  • Creation of a reverse draft in the room, or the fan spontaneously extinguishes the flame.
  • Malfunction of the central control board.

A master performs the diagnostics, first evaluating the injector and electrode’s performance and adjusting the distance as needed. The central board’s work is then assessed, and finally, the smoke evacuation system is revised.


The boiler ignites and extinguishes numerous times in a brief amount of time, which is linked to a malfunction in the combustion control system.

The reasons are:

  1. No draught in the chimney – Chimney may be blocked or there may be icing.
  2. Malfunction of the sensor itself – oxidation and broken wires, short circuit.
  3. Gas valve not set correctly – can be performed with special equipment.

Only a technician certified to perform repairs on gas equipment can resolve the issue.


The fan may not activate automatically after the boiler is started for the following reasons:

  1. Fan failure – broken or oxidized wires, short circuit.
  2. Chimney blockage – Flue gas does not go out.

You should remove the fan and make sure it is operational in order to solve the issue.


The issue arises at different central board faults, which can be caused by individual contact burning out as well as network voltage fluctuations. Most of the time, changing this part out for a new one is the only way to solve the issue.

Errors marked "D"

From a technical standpoint, these codes don’t represent a serious problem that impairs the boiler’s performance.

They make the following indications:

  • D1 – delay before the next boiler start-up. The code often occurs when forcibly resetting the equipment.
  • D2 – waiting time for the next water heating cycle.

  • D3 – waiting time before the next ignition, when it is necessary to ignite the boiler again if it failed the first time.
  • D4 – forced pause between starts (about 5 minutes).

Codes show up and vanish on their own. When these values are absent from the display, boiler operation can resume.

Relatively rare error codes

In the event that the gas equipment is experiencing wear and tear or has exceeded a decade in service, the display may exhibit unusual error codes.

  • F39 – faults in the thermistor, which are remedied by replacing the wiring or cleaning oxidized contacts.
  • F40 – high pressure in the system. Problems with the expansion tank or a clog in the quick-discharge valve.
  • F43 – Heat exchanger safety system activation, which may indicate a bled system or pump failure.
  • F50 – Faulty gas fittings, which may be the cause of a broken circuit board, as well as the valve. A forced reset of the boiler is used for diagnostics.

Occasionally, multiple codes appear simultaneously, signifying a significant malfunction in either a nearby or interdependent segment. Resetting the boiler frequently is not advised as this will only temporarily fix the issue rather than solve it.

General advice and recommendations for the correct operation of Ferroli boilers

It’s enough to heed these straightforward yet wise words of wisdom to lower the chances of experiencing breakdowns:

  • Do not use a faulty boiler if the codes appear on the display continuously. It is necessary to call a technician.
  • Be sure to connect the boiler to electricity through a stabilizer. This brand is vulnerable to drops, from which the board suffers.
  • Perform annual preventive diagnostics and do not forget to clean the heat exchanger from limescale.
  • Monitor the system pressure and remember to close the make-up tap.
  • Do not use the boiler at full capacity. If it is not enough for full-fledged heating of large areas, you need to choose a more powerful model.

Utilizing malfunctioning gas equipment can be fatal, so never do so. It is not permitted to open the boiler on your own during malfunctions, much less perform individual part repairs. Permitted specialists are the only ones who can perform this kind of work.

We solve the mysteries behind those annoying error messages that could cause problems for your heating system in our guide, "Faults and Error Codes of Ferroli Boilers." Whether it’s a mysterious code or a flashing light, we explain what they all mean, possible causes, and solutions. You don’t need to stand staring at your boiler in confusion, wondering what went wrong; we’ve got you covered with simple explanations and workable fixes to get your heating system operating again. Goodbye to cold evenings and welcome to a comfortable, mistake-free house!

Questions and answers

Frequently detect a bad exhaust gas smell. With the other boiler that was previously installed, this was not the case. How should one proceed?

Inspect the exhaust hood for blockages, particularly if the issue arises during the winter. A blockage that stops the exhaust gas from emptying entirely can be brought on by limescale. It is preferable to call a master and have the ventilation duct checked in any event.

The boiler displays code fh on the display when I turn it on after a prolonged period of non-use. I’ve read in the technical specifications that the system is being forced to expel air. Why does this code appear so frequently, and is it necessary to perform this procedure once a month?

This is not an error in procedure. Alternatively, you can press the corresponding button combination to bypass it. If you don’t unplug the boiler, it will save all of its settings and start up more quickly.

I don’t know why, but it takes five to seven seconds after startup for the ignition to happen. As a result, a distinctive popping sound occurs, the force of which rattles the boiler wall. I am aware that this is abnormal and that the instructions suggest lowering the voltage. How should one proceed?

Consider using a voltage stabilizer to connect to the boiler. The issue is especially prevalent for apartment building occupants. In the event that it is ineffective, a master must be called. There shouldn’t be a loud popping sound from the ignition.

Finally, it’s important to remember that Ferroli gas boilers can malfunction and experience breakdowns, which are documented using code values. You must contact an expert as soon as possible to identify and resolve the issues. If not, there will be a problem with the boiler that could endanger lives when used.

Error Code Description
F1 Ignition failure due to lack of gas supply or faulty ignition electrodes.
F4 Water pressure too low, potentially due to a leak or faulty pressure sensor.
F5 Overheating caused by a blocked flue, faulty pump, or circulation issues.
F8 Ignition lockout due to repeated ignition failures, often caused by air or gas supply issues.

Ferroli boilers are well known for their dependability and efficiency in keeping homes warm and cozy. But just like any other mechanical system, they are susceptible to malfunctions and error codes, which can be inconvenient and possibly interfere with heating. For homeowners to guarantee their boilers run efficiently, they must comprehend these issues, how to diagnose them, what causes them, and how to fix them.

When a Ferroli boiler displays an error code, it’s important to handle the situation methodically rather than becoming alarmed. Every error code denotes a distinct problem with the boiler system. Although deciphering these codes may initially seem difficult, homeowners can accurately diagnose the issue and take the necessary action if they have the necessary knowledge.

Ferroli boilers frequently have common error codes that point to problems like low water pressure, ignition problems, or sensor malfunctions. For instance, low water pressure can result in a system shutdown or decreased heating efficiency. Problems with the pilot light or gas supply can cause ignition failures, and malfunctioning sensors can cause the boiler to lose its ability to precisely control temperature.

Effectively resolving these error codes requires an understanding of their underlying causes. For example, a malfunctioning pressure relief valve or system leaks could be the cause of low water pressure. Airlocks or a closed gas valve are examples of problems with the gas supply that could be the cause of ignition failures. Wiring issues or the buildup of dirt or debris can cause sensor malfunctions.

Fortunately, homeowners can save time and money by fixing many of these errors and faults without the need for professional assistance. Minor problems can frequently be fixed with easy troubleshooting techniques like checking for leaks, bleeding radiators, or resetting the boiler. But it’s best to get help from licensed heating engineers if the issue continues or appears complicated.

In conclusion, even though Ferroli boiler problems and error codes can be unsettling, it’s important to maintain composure and take a methodical approach to the situation. Through comprehension of the error codes, identification of the underlying causes, and application of suitable remedies, homeowners can guarantee that their boilers sustain optimal performance, thereby ensuring year-round warmth and comfort in their homes.

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Sergey Ivanov

I like to help people create comfort and comfort in their homes. I share my experience and knowledge in articles so that you can make the right choice of a heating and insulation system for your home.

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