Ferroli F07 Fault Code: Causes, Fixes & Repair Costs
What does the Ferroli F07 fault code mean?
The F07 code is a blocking fault on Ferroli boilers, meaning the boiler pauses operation but may recover automatically once the underlying condition clears. It indicates that the air pressure switch contacts have closed earlier than expected during the startup sequence, or that flue gas temperatures have climbed too high. In plain terms, the boiler's safety system has detected that either the fan isn't creating the correct draught to safely expel combustion gases, or that the exhaust gases are running hotter than they should be. On certain Ferroli models — including the DOMIcondens HE 26C — F07 is specifically defined as a high fume temperature fault, while on other units it can relate to a pressure switch timing issue or an electronic parameter problem. It is worth knowing that if F07 triggers three times within a 24-hour period, Ferroli boilers will escalate this to an A04 lockout fault, which requires a manual reset and indicates a persistent underlying problem rather than a one-off glitch.
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
- Faulty or Failing Boiler Fan Common
The fan is responsible for creating enough draught to draw fresh air in and push flue gases safely out. If the fan motor is worn, the bearings are failing, or the fan speed is dropping, the air pressure switch won't see the pressure differential it expects and will trigger F07. A struggling fan is the single most common cause of this code on Ferroli boilers.
- Blocked or Restricted Flue Common
Any obstruction at the flue terminal — leaves, bird nests, debris after a storm, or a build-up of ice or snow in winter — can prevent gases from exhausting properly. This raises back-pressure and can cause both premature pressure switch closure and elevated flue temperatures. Always check the flue terminal externally as a first visual check.
- Faulty Air Pressure Switch Sometimes
The air pressure switch is a small diaphragm-operated switch that confirms adequate airflow before allowing the boiler to fire. If its diaphragm has perforated, if the connecting rubber hose has split or become blocked with condensate, or if the switch itself has failed electrically, it will send the wrong signal to the PCB regardless of whether the fan is working correctly.
- PCB or Internal Electronics Fault Rare
If the fan and air pressure switch both test correctly, the PCB (printed circuit board) that interprets the signals from these components may itself be at fault. A failing board can misread the pressure switch timing or falsely trigger the high temperature threshold. This is typically the last thing an engineer rules in rather than the first thing suspected.
How to fix it
- Check the flue terminal for obvious external blockages DIY safe
Go outside and look at where your flue exits the building. Check for leaves, a bird nest, accumulated snow, ice, or any debris sitting over the terminal grille. If you can safely reach it and remove loose debris by hand, do so. Do not insert anything into the flue pipe itself. If the terminal looks clear, move on to the next step.
- Reset the boiler once or twice to see if the fault clears DIY safe
Locate the reset button on your Ferroli boiler — it is usually marked with an 'R' or a flame symbol. Press and hold it for roughly five to ten seconds until the boiler attempts to restart. If it fires up and runs normally, monitor it over the next hour. If F07 returns promptly, do not keep resetting: repeated resets without fixing the root cause can damage the heat exchanger and fan. Remember that three F07 faults within 24 hours will escalate to an A04 lockout.
- Check that your gas supply is active DIY safe
Confirm that other gas appliances in your home — a gas hob, for example — are working normally. If there is no gas reaching the property, contact your gas supplier rather than an engineer. Also check that your gas meter isolation valve is fully open (handle in line with the pipe).
- Have a Gas Safe engineer inspect and test the fan Gas Safe engineer
A registered engineer will check the fan motor, measure its speed (tachometer signal), and confirm it is reaching the correct RPM before the pressure switch is expected to close. A slow or noisy fan that cannot generate sufficient draught will be replaced. Fan replacement on Ferroli boilers typically costs £180–£250 including parts and labour.
- Have the air pressure switch and connecting hose inspected Gas Safe engineer
The engineer will check the rubber hose connecting the fan housing to the pressure switch for splits, kinks, or condensate blockage. The switch itself will be tested with a manometer to confirm it opens and closes at the correct pressure differential. A faulty switch or hose is a straightforward and relatively inexpensive repair.
- Have the flue system professionally inspected and cleaned Gas Safe engineer
Even if the terminal looks clear externally, partial blockages can occur within the flue run itself. The engineer will check the full flue route, ensure joints are sealed correctly, and confirm that no flue gases are recirculating back into the air inlet — a situation that can cause both elevated temperatures and pressure switch anomalies.
- Have the PCB tested if all other components check out Gas Safe engineer
If the fan, pressure switch, hose, and flue all test correctly, the engineer will interrogate the PCB. PCB replacement on Ferroli boilers — depending on the model — typically costs £200–£300 all-in, though some older or less common models can command higher part prices. The engineer should confirm the board fault before ordering a replacement.
- Call a Gas Safe registered engineer if the fault persists or recurs Gas Safe engineer
If F07 keeps coming back after a reset, or if you have not been able to identify an obvious external blockage, this fault requires professional diagnosis. You can verify any engineer's Gas Safe registration at gassaferegister.co.uk and ask to see their ID card before work begins. Do not continue to reset and run the boiler repeatedly while waiting for an appointment.
Parts you may need
- Ferroli boiler fan / fan motor assembly · from £95
- Air pressure switch · from £35
- Pressure switch connecting hose · from £12
- Flue temperature sensor / NTC sensor · from £25
- PCB (control board) — model dependent · from £150
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 £120–£320, depending on the underlying cause.
Frequently asked questions
Is F07 a lockout fault or will the boiler recover on its own?
F07 is classified as a blocking fault on Ferroli boilers, which means it can clear automatically once the condition that triggered it resolves — for example, if a temporary pressure fluctuation settles. However, if the fault is caused by a failing fan, a physical blockage, or a faulty switch, it will keep returning. Crucially, if F07 occurs three times within any 24-hour window, your Ferroli will escalate to an A04 lockout, which requires a manual reset and means the boiler has identified a persistent rather than a one-off problem.
Can I fix Ferroli F07 myself, or do I need an engineer?
There are a couple of checks a homeowner can safely carry out: looking at the external flue terminal for obvious blockages and resetting the boiler once or twice to see if the fault clears. Beyond that, diagnosing whether the fan, air pressure switch, or PCB is at fault requires specialist test equipment and, because the boiler is a gas appliance, a Gas Safe registered engineer. Attempting to bypass or replace internal components yourself is both unsafe and illegal under UK gas safety regulations.
How much does it typically cost to fix a Ferroli F07 fault?
Most people with this fault end up paying between £120 and £320, depending on what needs replacing. A straightforward air pressure switch or hose replacement sits at the lower end, while a fan replacement usually comes in at £180–£250 including labour. If the PCB turns out to be the culprit, costs can rise to £300 or beyond depending on the Ferroli model, as some control boards are more expensive to source than others — worth bearing in mind if your boiler is over ten years old.
Could a blocked flue really cause F07 on my Ferroli boiler?
Yes, a blocked or partially obstructed flue is one of the most common triggers. When exhaust gases cannot escape freely, two things happen: the fan has to work harder and may struggle to build the pressure the switch expects, and the temperature of the gases backing up in the system rises. Both of these conditions are exactly what F07 is designed to detect. After storms, periods of heavy snowfall, or if you have noticed birds nesting near your flue terminal, always check the terminal as your first step.