Ideal F3 Fan Fault

April 18, 2023

F3 Fan faults are a common problem in many boilers and can cause undue wear and tear on heating systems.

There are a variety of reasons why an F3 error occurs, but it's primarily due to a malfunction with the fan. Although other factors can cause these errors, most F3 errors relate to the fan in some way. Before we can determine how to repair an F3 error, we should first understand what causes it.

What Does the F3 Fault Code Mean?

The F3 fault code is a boiler fault, one of the most common boiler faults you will come across. The F3 fault is known as a 'fault with fan', which means a problem with the fan assembly inside your boiler.

The purpose of the fan is to circulate air through your system, which helps to prevent condensation from forming on the heating elements. If you have an F3 fault, your boiler has detected an issue with one of these fans.

This can be due to any number of reasons, but it's essential to identify what is causing your boiler to give you this message. The good news is that many boilers have built-in diagnostics that can help you identify what's going wrong with your system.

What Causes the F3 Fault Code?

When a boiler's fan is not working properly, it can cause the F3 fault code to appear on the boiler's display screen. There are several reasons why you might see this error code on your boiler's display screen:

Fan Speed is Too Low

If your boiler keeps giving you the Fan fault code, it could mean that your fan speed is too low. This means that the boiler needs to be serviced as soon as possible because, if left unchecked, this fault can cause serious damage to your boiler and its components.

Fan Bearings are Jammed or Burnt Out

If your boiler keeps giving you the Fan fault code, it could mean that your fan bearings are jammed or have burnt out. The bearings are responsible for keeping your fan spinning smoothly, so they need to be checked regularly to ensure they don’t become damaged over time which would result in this fault code being shown on your display panel.

Boiler Wiring has Become Loose or Damaged.

If the wiring inside your boiler has become loose or damaged in some way, it can cause problems with your boiler’s functionality. This may cause it to overheat or blow fuses. If this happens, it is essential to contact an expert as soon as possible so they can fix the issue before it worsens and leads to more problems for you and your family.

Boiler Wiring has Become Wet.

Water damage is one of the most common reasons for boilers to malfunction and break down completely over time. If water has leaked into your wiring system, this can cause severe damage that will require professional repairs from an experienced technician to correct.

The Fan is no Longer Functional.

The fan may have become dislodged from its position, or there may be a fault with the motor or wiring. You'll need to check that the fan has not become loose and move it back into position if necessary. If this doesn't solve the problem, replace the fan. Contact a local heating engineer to repair it.

Can I Fix My Boiler with The F3 Fault Code?

If you have an issue with your boiler and it displays an F3 fault code, don't panic! In most cases, this simple fix can be done by yourself in under an hour. However, if you're not sure what to do, then please, call a professional engineer to come out and take a look at it for you before attempting any repairs yourself!

How To Fix an F3 Fault Code

If your boiler is giving an F3 Fan Fault code, this will be due to a problem with the fan itself. The most common cause of this fault is that the flexible coupling has come loose or damaged, which means that the fan can no longer operate properly, which can damage other parts of the system.

The best way to fix this problem is by replacing the fan and coupling altogether. While you can attempt to repair them yourself, it’s a good idea to call in a professional for this job as it can be quite tricky and time-consuming.

You’ll need some basic tools like an Allen key (hex key) set, pliers, and wire cutters to complete this task, but if you don’t have access to these, you can always buy them online or at any DIY store nearby.

How does the fan work?

The fan is part of your boiler's combustion system, which includes a burner, heat exchanger, and exhaust flue. When you turn on your boiler and start heating water, the flame burns in the burner and heats the gas sitting in your heat exchanger. The heat from the flame heats a tube in the heat exchanger called a "flue" that leads to the exhaust flue on your roof or wherever it leads outside of your home. This hot gas then goes through another tube inside your furnace called a "condenser," where it cools down and condenses back into liquid form before going back down into another tube in your furnace called an "evaporator." The evaporator then sends this liquid through pipes in your home to heat water or air for you to use for heating purposes.


An F3 fault is one of the most commonly seen types of boiler fault code, making it especially important to understand what it means and how you can fix it quickly. If you have ever experienced an F3 code, or are seeing an F3 on your gauge now, look at our guide for more information about what this fault means and how you can troubleshoot it!

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