🕑 10 minutes read

After a busy day, you return home on a cold night, only to find your Vaillant boiler has stopped working, showing an unfamiliar message, "f61." Feeling a bit worried is ok, but there's no need to panic.

In this guide, we'll provide the necessary information to efficiently address this issue, sure enough not to leave you out in the cold.

Vaillant boilers are typically reliable and efficient, but they can experience issues like any other boiler.

What is the Vaillant F61 Fault Code?

The gas valve's duty is to control gas flow to the burner, while the PCB manages it. The PCB gathers data from sensors throughout the boiler and heating system. This error often results in a loss of heating and hot water.

The Vaillant F61 fault code is often caused by component failure or faulty wiring between the PCB and gas valve.

F61 vaillant boiler fault

While resetting the boiler may provide temporary relief, it's essential to have a Gas Safe registered engineer diagnose and resolve the issue for a lasting solution. Understanding and addressing the F61 error promptly ensures your Vaillant boiler continues to function effectively.

F61 is one you shouldn't ignore out of all the fault codes. It's an indicator that the gas valve has failed to switch on after five attempts. This points to an issue with the gas system, a component failure, or an underlying fault that could be causing a strain on the boiler's normal function.

F61 is one you shouldn't ignore out of all the fault codes. It's an indicator that the gas valve has failed to switch on after five attempts. This points to an issue with the gas system, a component failure, or an underlying fault that could be causing a strain on the boiler's normal function.

Since the F61 Fault Code involves gas, it's essential to have a Gas Safe registered engineer handle the boiler repair.

What Does F61 Mean on a Vaillant Boiler?


When your heating system displays the F61 Vaillant fault code, it alerts you to a potentially serious problem related to the gas valve operation.

Here's the critical aspect to remember:

  • The boiler has a built-in safety mechanism that allows a maximum of 5 attempts to ignite before shutting down to prevent any hazardous gas build-up.
  • Vaillant F61 fault code indicates that the gas valve has not opened within these attempts, signalling issues that must be addressed promptly for the boiler's safety and proper operation.

What Causes the Vaillant F61 Fault Code?

F61 fault code on Vaillant boiler is a frequently encountered boiler issue among homeowners. It can arise from a range of issues, such as faulty gas valves, gas supply problems, wiring complexities, PCB faults, or boiler component malfunctions.

We will thoroughly explore the typical reasons behind the Vaillant F61 error code. Pinpointing the origin of an F61 fault resembles solving a minor mystery, given its potential association with various gas system problems in the boiler.

The F61 Vaillant fault code commonly arises from various issues, each requiring attention to ensure your boiler operates smoothly:

Faulty Gas Valve The-PCB-section-of-a-Vaillant-boiler

When the gas valve malfunctions, possibly due to being stuck or seized, the boiler may shut down. A Gas Safe registered engineer can diagnose and fix this issue.

Gas supply problems

This can disrupt the proper functioning of your boiler. Inadequate gas pressure or blockages in the gas line can prevent the gas valve from receiving the necessary fuel to ignite the boiler. Issues with the gas supply or gas valve actuation fault can trigger the F61 error code. Only a Gas Safe registered engineer can accurately diagnose and resolve these problems.

Wiring Issues Wiring-system-of-a-Vaillant-boiler

Loose wiring between the PCB and gas valve or problems with the wiring harness can disrupt communication and trigger the F61 error code. These issues often require professional intervention to rectify.

PCB Faults

A faulty PCB, caused by component failure or communication errors, can also lead to the F61 error code. It's crucial to have a Gas Safe registered engineer diagnose and repair PCB faults promptly.

Electrical faults

This can lead to issues with the gas valve. A defective or miscommunicating PCB can cause misfires or a lack of power to the gas valve, resulting in errors like Vaillant F61. Wiring problems may also prevent the valve from receiving the correct signals to open.

Component Malfunctions Inner-side-of-a-Vaillant-boiler

When your Vaillant boiler displays the F61 error code, it typically indicates a malfunction with various components. These components include the gas valve, ignition lead, electrode, sensors, pressure, temperature, fan, pump, combustion chamber, and burner. These issues can disrupt the boiler's operation and lead to the error code. To accurately diagnose and fix these component failures, it's essential to enlist the expertise of a Gas Safe registered engineer. They can identify the specific problem and perform the necessary repairs to restore your boiler's functionality.

If your boiler detects an F61 error, it will "lockout," stopping its operation until the issue is resolved. This safety feature prevents additional damage or potential hazards.

At Serviceteam, our skilled heating engineers stand prepared to assist you with emergency boiler repairs and boiler installations throughout London.

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How to Fix F61 Vaillant Fault Code?


Before breaking into a cold sweat, it's essential to note that resolving a Vaillant F61 fault code isn't always a task for technicians. Sometimes, simple solutions can restore your boiler's functionality.

Basic Troubleshooting

  • Turn Off The Boiler
    Begin by turning off the boiler and checking that the gas supply is uninterrupted.
  • Check the System Pressure
    Ensure the system pressure is within the recommended range; low pressure can mimic an F61 error.
  • Check Your Gas Supply
    Inspect the gas flue for any blockages that might be impeding the expulsion of gas.
  • Reset Your boiler
    A boiler reset reset may be all that's needed. Turn off the boiler, wait a few minutes, then turn it back on. Bleed Your Radiators.
  • Bleed Your Radiators.
    A heating engineer is bleeding a radiator in a London property Sometimes, air in the system can create pressure issues that lead to an F61 error.

Advanced Solutions

  • If the valve is visibly damaged or starts operating sporadically, it's time to bring in professional help to repair or replace it.
  • Consider a full boiler service. Regular maintenance can catch issues before they lead to error codes and breakdowns.

How to Prevent F61 Vaillant Fault Code?

Being proactive can save you from a cold snap. Preemptive measures can circumvent an F61 surprise and ensure your Vaillant boiler's smooth, efficient operation.

1. Regular Maintenance

  • Schedule annual boiler servicing to keep your boiler in top shape and to diagnose and address any potential issues before they lead to faults.
  • During a service, a qualified engineer will clean the gas valve, check all sensors and safety devices, and ensure the boiler is in tune with manufacturer specifications.

2. Monitor the System

  • Keep an eye on your boiler's performance. Irregularities in ignition or unusual noises can be early warning signs of a failing gas valve.
  • A vigilant eye can help you take action before a fault occurs.

When to Call in the Professionals?


While some F61 events can be resolved with a reset or basic checks, some situations are clearly a call to action for professional help:

  • Repetitive or persistent F61 errors indicate a more significant problem that needs expert attention.
  • Any visible damage or defects in the boiler's components, particularly the gas valve, should not be addressed without professional help.
  • If you're not confident in diagnosing or addressing an F61 error, it's always best to call a Gas Safe registered engineer.

Call Serviceteam Heating Professionals

Contact Serviceteam Professionals for all your boiler needs. We offer round-the-clock service in London and handle emergency breakdowns and installations alike.


How often should I service my Vaillant boiler to prevent an F61 fault?

We recommend an annual service for all Vaillant boilers. Regular maintenance can prevent many issues, including the faults associated with the F61 error.

What's the typical cost to repair a Vaillant F61 fault code?

The repair cost will vary depending on the cause and the parts or labour required. A gas engineer can provide a quote after diagnosing the issue.

At serviceteam, our prices start from £

Can I reset the boiler multiple times to try and clear the F61 code?

While one reset following an F61 error is reasonable, repeated resets without addressing the issue can damage the boiler further. If the problem persists, seek professional assistance. By understanding the F61 fault code and its potential issues, you've armed yourself with the knowledge to tackle the issue head-on. Whether you attempt a DIY fix or recognise the need for professional intervention, you're better equipped to keep your Vaillant boiler warm and work through those long winter nights.

Remember, safety first, and may your home always be a cosy, code-free haven.

When dealing with boiler problems, we advise against DIY fixes unless you're a trained boiler professional yourself.

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