What Does the Vaillant F28 Fault Code Mean and How Can You Fix?
Estimated reading time: 4 minutes
Table of contents
A faulty boiler can be frustrating, especially when it stops working unexpectedly. If you own a Vaillant boiler and see the F28 fault code, don’t worry—it’s a common issue that can often be fixed with some basic troubleshooting.
What is the Vaillant F28 Fault Code?
The Vaillant F28 fault code is an ignition fault that occurs when your boiler fails to ignite after three consecutive attempts. When this happens, the boiler shuts down as a safety precaution, leaving you without heating or hot water. This error is commonly found in several Vaillant boiler models, including:
- Vaillant ecoTEC Pro
- Vaillant ecoTEC Pro Plus
- Vaillant Turbomax Plus 824/828E
Common Causes Of Vaillant F22 Error
The F28 fault code is generally caused by either an ignition issue or a problem with the gas valve. The most common reasons include:
1. Gas Supply Issues
If there is no gas supply to your boiler, it will fail to ignite. You can check for a gas supply issue by turning on other gas appliances in your home, such as a gas stove or fireplace. If they do not work, there might be an issue with your energy provider, a meter that needs topping up, or ongoing gas infrastructure maintenance in your area.
2. Faulty Gas Valve
The gas valve regulates the flow of gas into the boiler. If the valve is faulty or not opening properly, the boiler won’t receive the necessary fuel for ignition. This issue can stem from wiring problems or mechanical wear and tear over time. You can shop for Vaillant gas valves here.
3. Wiring Faults
The gas valve is electronically connected to the printed circuit board (PCB), which controls various boiler functions. If there is a loose or broken wire between these components, the gas valve may fail to operate correctly, causing the boiler to shut down.
4. Faulty Electrodes
Ignition electrodes create the spark needed to ignite the gas in your boiler. If the electrodes are dirty, worn, or broken, the ignition process will fail, resulting in the F28 fault code.
5. Frozen Condensate Pipe
During winter, the condensate pipe, which expels waste gases and condensation from the boiler, can freeze. A blocked or frozen condensate pipe can lead to ignition failure.
6. PCB (Printed Circuit Board) Fault
The PCB is the boiler’s central control unit, responsible for regulating all functions. If it fails, the boiler will not receive the necessary signals for ignition.
Can I Fix Myself?
Before calling a Gas Safe Engineer, you can try these simple troubleshooting steps:
- Reset the Boiler – Turn the boiler off and on again using the reset button. Check the user manual for model-specific instructions.
- Check Your Gas Supply – Test other gas appliances in your home to ensure the gas supply is working.
- Inspect the Flue and Air Intakes – Look for blockages in the flue or air intake pipes, as these can prevent proper airflow.
If the F28 fault code persists, it is advisable to call a Gas Safe registered engineer.
When Should You Contact a Gas Safe Engineer?
If basic troubleshooting does not resolve the issue, you should seek professional help. A Gas Safe engineer can:
- Inspect and replace faulty components such as the gas valve, electrodes, or PCB.
- Diagnose and fix wiring faults.
- Unblock a frozen condensate pipe safely.
Should You Consider a New Boiler?
If your boiler is old and frequently showing error codes like F28, it may be time to upgrade to a newer, more efficient model. Many modern boilers come with advanced safety features and better energy efficiency.
Conclusion
The Vaillant F28 fault code is a common issue that indicates an ignition failure, often caused by gas supply issues, faulty components, or a frozen condensate pipe. While some simple checks can be performed by homeowners, persistent issues require the expertise of a Gas Safe registered engineer. If your boiler frequently experiences faults, consider replacing it with a newer model for better efficiency and reliability.