Is a Vaillant F28 error code a mole you can whack back down, or is it time to see a professional?
A Vaillant F28 is a false start, literally.
Delve down below to reveal your immediate boiler destiny and the reason you're this deep in Google.
It's most likely going to need a boiler engineer visit (but there is one reason which might save you that fate).
Key points:
F28 Error Code: Indicates an ignition problem where the boiler fails to ignite after three attempts.
Common Causes: Possible issues include gas supply problems, a faulty gas valve, or an ignition electrode issue.
Basic Troubleshooting: Check the gas supply, reset the boiler, and ensure there’s no blockage in the flue.
When to Call a Professional: If basic troubleshooting doesn’t work, contact a Gas Safe engineer to inspect and fix the issue.
Resolving the Vaillant boiler F28 error
If your boiler is displaying an error code, you might be tempted to simply restart your boiler and ignore the code. After all, that’s how you fix anything from laptops to Stepford wives.
However, this is unlikely to resolve the issue and ultimately your boiler will stop operating for three important reasons:
To protect the boiler from damage
To keep everyone on the property safe
To annoy you on a very cold day
It is also important to never tamper with the boiler yourself, or open the casing, as this can be dangerous. Instead, the best thing you can do is to get your boiler investigated and fixed by a qualified Gas Safe Engineer.
What causes the Vaillant boiler F28 error?
The Vaillant boiler F28 error code is displayed on the following Vaillant boiler models:
ecoTEC Pro Plus
Turbomax Plus 824/828E
The F28 code is displayed when your boiler fails three ignition attempts, resulting in the boiler halting operation and turning off.
Vaillant officially defines the F28 error code as an ignition fault. There are many potential causes to this problem including an insufficient supply of gas, a faulty electrode or ignition lead.
Currently, the manufacturer doesn’t acknowledge the heinous work of gremlins.
Therefore, the causes of the F28 fault can be broadly categorised into either an ignition fault or a gas valve fault.
This issue results in a boiler failure since the ignition is required to light the gas and create the flame that the cold water passes over to become heated.
Since it is faulty, the hot water can no longer become heated, meaning no hot water can be supplied to your taps or your central heating system.
If you’re the first in your house to spot the F28 boiler error, you might still get a shower if you don’t tell anyone else first.
Think you may have an ongoing issue with your boiler? Check our list of the top 10 boiler problems common in all types of boilers.
Vaillant F28 fault code fixes
When diagnosing the cause of the f28 fault code on your boiler, a registered Gas Safe Engineer will likely inspect the following boiler components:
Gas supply issue
One of the most common causes of an f28 error code being displayed is a gas supply fault.
i.e. no gas supply to your boiler
It’s really just the boiler equivalent of missing your own mouth with a spoon while eating.
You can easily test if this is the likely cause yourself by attempting to turn on other gas appliances in your home and seeing if they work or not.
i.e. a cooker, or fire
If there is no gas supply, this may be caused by your energy company cutting off supply, gas infrastructure work currently taking place in your area, or, you may have simply not topped up your meter (if you have one).
Looking to pay for your new boiler monthly? Refer to our boilers on finance guide.
Learn all about combi boilers in our what is a combi boiler.
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Faulty gas valve
A gas valve fault is another common cause of an f28 error.
The gas valves' main role is to control the supply of gas into the boiler, so when there is an issue no fuel can be ignited to heat the water.
A fault with the gas valve can be a result of either a wiring or mechanical fault.
Unfortunately, nobody can help you with Uncle William’s faulty gas valve - just limit his onion intake.
Cost to fix: £150-300
Wiring fault
For example, boiler components are connected electronically to the printed circuit board (PCB), which is the control centre of the boiler, responsible for controlling and coordinating the various boiler components.
Think of it as your boiler’s brain - a wiring fault in your brain also comes with plenty of errors.
Therefore, if a wire is loose or disconnected between the gas valve and PCB, the signals will no longer be transmitted, resulting in the gas valve malfunctioning, and causing the boiler to shut off.
Cost to fix: £100-500
Is your boiler leaking or losing pressure? Use our quick and easy tool to get your fixed price boiler replacement.
Mechanical fault
Alternatively, the gas valve may not be working due to a mechanical fault. With time, the valve is susceptible to wear and tear, resulting in the valve sticking.
A gas valve that is prone to sticking will no longer be able to reliably carry out its function – to open and close whenever gas is required. As a result, this can cause the boiler to shut off and display the f28 error code.
Cost to fix: £100-300
PS You may be interested in Gas Engineer Allen Hart explaining the most common boiler problems and how you can resolve them in the video below:
Faulty electrodes
When the gas enters the boiler via the valve, it needs to be ignited by the electrodes, however, if they are faulty, they will no longer be able to ignite the gas and create the flame.
Your faulty electrodes just grew apart. They stopped truly caring and putting in the effort in the early days. Maybe they’re just tired at night - maybe they’re stressed at work. But the romance is gone, and they can’t seem to ignite the flame.
Maybe we’re overthinking this.
Over time, the electrodes can become worn and may need to be cleaned or replaced, in which case a registered Gas Safe Engineer can do this.
Cost to fix: £100-300
Frozen condensate pipe
The condensate pipe’s job is to direct toxic flue exhaust fumes/vapour/residue to the outside of your property, so when this becomes blocked it can be a safety hazard, hence why the boiler will shut off until the issue is resolved.
When it comes to a frozen condensate pipe, it’s either cold showers or toxic fumes, and you don’t get to choose.
Traditionally, condensate pipes tend to freeze in winter, resulting in a blocked pipe. To resolve this, a Gas Safe Engineer can defrost the pipe to get the contents flowing again.
Thankfully, modern boilers such as Worcester Bosches Greenstar Range are equipped with CondenseSure, this is a feature designed to prevent condensate pipes from freezing.
Cost to fix: £50-100
PCB fault
The printed circuit board is the processing unit of the boiler and is wired up and receives signals from many of the boiler’s components, controlling their function and ensuring they coordinate together as intended.
Here’s an image of a PCB:
However, if a wire is loose or disconnected from a component and the PCB, or the PCB is faulty, it could result in the boiler shutting off and displaying the f28 error code.
For Mother’s Day this year, we recommend getting your mum a card that says “You’re the printed circuit board of this house”. You can thank us later.
Cost to fix: £100-500
Check our new boiler costs guide and use our boiler size calculator if you want to get a better understanding of how our fixed-price boiler quote tool works.
Is your Vaillant boiler experiencing some of the brand's most common fault codes? We have covered many Vaillant boiler error codes in the following guides:
Fixing the Vaillant F28 Error Code
The best way to resolve the F28 error code is to seek the help of a registered Gas Safe Engineer, who will be able to diagnose and repair whatever is causing the f28 code to be displayed.
If you’re aiming to get the best deal on a new boiler, consider getting a quote from us, here’s why:
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