Vokera Boiler Error Codes: Causes & How to Fix Them

Last Updated on January 28, 2025

If you own a Vokera boiler, it’s essential to understand its error codes. These codes are a built-in diagnostic tool designed to highlight issues affecting your boiler. 

Whether you’re a homeowner or a landlord, knowing what these error codes mean and how to address them can save time, effort, and money.

In this article, we’ll provide a comprehensive guide to Vokera boiler error codes, their causes, and potential fixes.

Why Do Vokera Boilers Display Error Codes?

Vokera error codes are safety mechanisms that protect your boiler from severe damage and ensure efficient performance. When something goes wrong, the boiler shuts down and displays an error code to help identify the issue.

Ignoring these warnings can lead to further damage or unsafe conditions. Therefore, understanding and addressing these error codes is critical.

Common Vokera Boiler Error Codes and How to Fix Them

Vokera boilers are built with advanced technology to display error codes when something goes wrong. Below is a detailed guide on the most common Vokera boiler error codes, their causes, and actionable steps for troubleshooting.

1. Error Code A01 – Ignition Failure

What it Means:
The boiler has failed to ignite after three attempts. Without ignition, the boiler cannot produce heat or hot water.

Possible Causes:

• Gas supply is turned off or insufficient.
• Faulty ignition electrode or gas valve.
• Low gas pressure in the system.
• Blockage or debris in the burner.

How to Fix:

1. Check Gas Supply:
   • Ensure the gas supply is turned on and the gas meter is functioning correctly.
   • If using a prepay meter, make sure it has credit.
2. Inspect the Ignition Electrode:
   • Look for any signs of wear or damage. Replace if necessary.
3. Reset the Boiler:
   • Turn off the boiler, wait for a few minutes, and restart it.
4. Call a Gas Safe Engineer:
   • If the issue persists, contact a Gas Safe registered engineer to inspect and repair the gas valve, burner, or other components.

2. Error Code A03 – Overheating

What it Means:
The boiler has detected excessively high temperatures and has shut down to prevent damage.

Possible Causes:

• Blocked heat exchanger restricting water flow.
• Faulty circulation pump failing to circulate water.
• Air trapped in the system causing hot spots.
• Thermistor (temperature sensor) malfunction.

How to Fix:

1. Bleed the System:
   • Bleed radiators to release trapped air and restore proper water flow.
2. Check the Pump:
   • Ensure the pump is operational. Listen for strange noises or vibrations that may indicate a fault.
3. Inspect the Heat Exchanger:
   • A blocked heat exchanger may require professional cleaning.
4. Seek Professional Help:
   • If the boiler continues to overheat, a qualified engineer can check for underlying issues with the pump or thermistor.

3. Error Code A04 – Low System Pressure

What it Means:
The system pressure has dropped below the safe operating level, typically below 1 bar. Boilers require adequate pressure to heat water and circulate it effectively.

Possible Causes:

• Leaks in the central heating system or radiators.
• Faulty pressure relief valve.
• Insufficient water in the system.

How to Fix:

1. Check the Pressure Gauge:
   • Locate the gauge on the boiler. If it’s below 1 bar, you’ll need to top up the pressure.
2. Top Up the Water:
   • Use the filling loop to add water to the system until the pressure reaches 1.5 bar.
3. Inspect for Leaks:
   • Look for signs of water leakage around the boiler, radiators, and the pipes. Address any leaks promptly.
4. Contact an Engineer:
   • If the pressure drops repeatedly, a Gas Safe registered engineer may need to check for internal faults, like a damaged expansion vessel or pressure relief valve.

4. Error Code A41 – Flue System Issue

What it Means:
The flue system, responsible for venting exhaust gases, has a problem, which can affect boiler safety and efficiency.

Possible Causes:

• Blocked or obstructed flue.
• Incorrect installation of the flue pipes.
• Flue sensor or fan malfunction.

How to Fix:

1. Inspect the Flue:
   • Ensure the flue is clear of debris, such as leaves or snow, and properly fitted.
2. Check for Proper Ventilation:
   • Make sure the boiler is in a well-ventilated space to prevent blockages.
3. Test the Fan and Sensors:
   • A malfunctioning fan or sensor may need replacement by a professional engineer.

5. Error Code A07 – NTC Thermistor Fault

What it Means:
The NTC thermistor, which measures water temperature, is not functioning correctly.

Possible Causes:

• Damaged or faulty thermistor.
• Loose or corroded connections.

How to Fix:

1. Inspect the Thermistor:
   • Check for visible damage. A replacement may be necessary.
2. Verify Connections:
   • Ensure the wiring and connections are secure and free from corrosion.
3. Get Professional Assistance:
   • Replacing the thermistor is best handled by a professional engineer.

6. Error Code E02 – Fan Fault

What it Means:
The fan that helps expel combustion gases is not working correctly.

Possible Causes:

• Blocked fan due to dust or debris.
• Damaged fan motor.
• Faulty air pressure switch.

How to Fix:

1. Clean the Fan:
   • Remove dust or debris buildup from the fan blades.
2. Test the Fan Motor:
   • If the motor is damaged, it will need to be replaced.
3. Inspect the Air Pressure Switch:
   • Ensure the switch is functioning properly to detect airflow. Call an engineer for repairs.

7. Error Code E05 – High Flow Temperature

What it Means:
The temperature of the water flowing through the system is too high.

Possible Causes:

• Blockages in the system restricting water flow.
• Malfunctioning circulation pump.
• Faulty temperature sensors.

How to Fix:

1. Flush the System:
   • Perform a power flush to remove blockages or sludge buildup.
2. Check the Pump:
   • Ensure the circulation pump is running efficiently. Listen for unusual noises.
3. Test the Temperature Sensors:
   • Faulty sensors may need replacement.
4. Call an Engineer:
   • Persistent issues should be addressed by a qualified professional.

Preventing Vokera Boiler Issues

To minimise the likelihood of encountering error codes, follow these maintenance tips:

1. Schedule Regular Servicing: Annual servicing by a qualified engineer ensures your boiler operates efficiently and safely.
2. Monitor System Pressure: Regularly check the boiler’s pressure gauge and top up when necessary.
3. Bleed Radiators: Prevent trapped air in your system by bleeding your radiators when needed.
4. Inspect for Leaks: Check for visible signs of leaks around your boiler and pipes.
5. Keep the Flue Clear: Ensure the flue is free from obstructions, such as debris or snow.

When to Call a Professional

While some fixes can be performed by homeowners, others require the expertise of a Gas Safe registered engineer. Call a professional if:

• You’re unsure about handling the boiler components.
• The error persists after troubleshooting.
• The boiler displays multiple error codes.

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Simply fill out our quick and easy online form, answer a few simple questions about your current setup and needs, and we’ll get back to you with a personalised quote within minutes.

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Conclusion

Understanding Vokera boiler error codes can save you from unnecessary stress and expenses. While some issues are simple to resolve, others may require professional intervention. 

By keeping your boiler well-maintained and addressing errors promptly, you can ensure its long-term efficiency and safety.

If you’re experiencing persistent boiler problems, don’t hesitate to contact a qualified heating engineer. Proper care and maintenance will keep your Vokera boiler running smoothly for years to come.