Vaillant F28 Error Code: Causes and Solutions

Have you found the Vaillant F28 error code on your Ecotec boiler’s display? Fear not. In this article, we explain everything you need to know about the F28 fault code and how to fix it and when to call a professional boiler repair company.

Jump to a topic:

1. What is Vaillant F28 Fault Code?
2. Possible Causes of the F28 fault
   1. Gas Supply Problems
   2. Faulty Ignition Electrode
   3. Issues with the Gas Valve
   4. Faulty PCB
   5. Blocked or Damaged Flue
   6. The Condensate Pipe
   7. The Ignition Electrode
3. How to Prevent the F28 Fault

What is the Vaillant Ecotec F28 fault code?

The Vaillant Ecotec F28 fault code indicates the boiler is experiencing a flame detection fault. The fault is displayed when the boiler is not detecting a flame.

When the F28 error is displayed, your boiler will automatically shut down as a safety precaution. If the boiler was to continue to operate while the error is present, it could lead to more severe damage to the boiler.

In addition to further damage, if the boiler continued to operate during the error, it could put your home at risk of harmful gasses .

Possible causes

There are a few reasons why your Vaillant boiler may be displaying the F28 error code. We will explain some of the most common causes in the next section of this article.

Gas supply problems

We will begin with the most common reason for the F32 fault. If you have a prepayment meter, make sure you have enough credit. If you run out of credit, the gas supply will turn off, and the error code will be shown.

If you aren’t using a prepayment meter, the gas supply could still be a cause. Low gas pressure or a block in the gas line will cause the fault.

A boiler engineer will be able to test the gas valve by checking the voltage across the terminals using a multimeter. If there’s no voltage, your gas valve may be faulty and need replacing.

Faulty ignition electrode

The ignition electrode is responsible for creating a spark that ignites the gas in your boiler. If the electrode is dirty, damaged, or faulty, it may not be able to create a spark, resulting in the F28 error code.

This issue is easily prevented by having a boiler engineer service your boiler. As part of the service, they will clean the components inside your boiler to prevent dirt and grime from building up.

It is possible that the ignition electrode is just dirty, in which case an engineer can clean it with a soft brush restoring the connection. However, if the electrode is damaged, it will need to be replaced.

Issues with the gas valve

The gas valve regulates the flow of gas to your boiler. If the valve is faulty, it may not allow enough gas to flow through, which can result in the F28 error code.

If the gas valve is faulty, it will need to be replaced. You should always have a professional replace the gas valve, as it involves working with gas.

Faulty PCB

The Printed Circuit Board (PCB) is the brain of your boiler, it controls all of the functions and components of your boiler. If the PCB is faulty, it may not be able to send the correct signals to your boiler, resulting in the F28 error code.

If the PCB is faulty, it may need to be replaced. A technician can test the PCB by checking the voltage across the terminals using a multimeter. If there is no voltage, the PCB may be faulty and need to be replaced.

Blocked or damaged flue

The flue is responsible for removing the byproducts of combustion from your boiler. If the flue is blocked or damaged, it can cause the F28 error code to appear.

Check the flue for any blockages or damage. If the flue is blocked, you will need to clear it. If it is damaged, you will need to have it repaired or replaced.

The condensate pipe

The condensate pipe removes toxic fumes from your boiler to prevent dangerous gases from leaking inside your home.

During the winter, condensate pipes can freeze, preventing the pipe from working correctly. As a result, the boiler will shut down as a safety measure and show an error code.

A Gase Safe engineer will inspect the pipe to see if it is blocked or frozen. If it’s blocked, the technician will remove the blockage; if it’s frozen, they will safely defrost the pipe.

Inspect the ignition electrode

Check the ignition electrode for dirt or damage. If it is dirty, clean it with a soft brush. If it is damaged, it will need to be replaced.

If the ignition electrode is dirty, clean it with a soft brush. If it is damaged, it will need to be replaced. If you are comfortable working with boilers, you can replace the ignition electrode yourself, or you can call a professional to do it for you.

How to prevent the F28 fault

As with all boiler faults, prevention is much cheaper than cure. We’ve outlined a few steps you can take to keep your boiler running and your home warm:

1. Schedule Regular Maintenance: The number one way to prevent unexpected boiler faults is to have your boiler serviced by a qualified engineer at least once a year. This will help to identify and fix any issues before they become bigger problems. Additionally, maintenance helps to ensure the efficiency of your boiler, saving you money on energy bills and repairs.
2. Check the Flue Regularly: Keep an eye on your boiler’s flue to ensure that it is free from debris and blockages. You can also have your flue checked by a qualified engineer during your annual maintenance visit.
3. Keep Your Gas Supply Regular: Ensure that you have a consistent supply of gas to your home. You can do this by contacting your gas supplier if you suspect any issues with your supply.
4. Don’t Ignore Warning Signs: If you notice any unusual sounds or smells coming from your boiler or if it is not functioning properly, don’t ignore them. Contact a qualified engineer as soon as possible to diagnose and fix the issue.

More Guides on Valliant Faults

• How to Reset a Vaillant Boiler
• How to Fix an F22 Fault on a Vaillant Boiler
• How to Fix an F75 Fault on a Vaillant Boiler
• How to Fix an F32 Error on a Vaillant Boiler

About the author

Trades Team are experts in Heating, Plumbing and Gas Services. We have 15 years of experience providing expert Boiler Repair and Boiler Servicing to homes and businesses across the Southeast. Learn more about Trades Team.