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Last updated: 2nd August, 2023


Vaillant F62 Error Code - How To Fix

Vaillant F62 Error Code - How To Fix

Key takeaways

  • The Vaillant F62 indicates a problem with the gas valve.
  • PCB issues, intermittent connection and a stuck gas valve can cause an F62 code.
  • F62 fault codes must be fixed by a Gas Safe registered engineer, which all of our iHeat engineers are.

Error codes on boilers can be a confusing and frustrating topic, here at iHeat we want to make everything about boilers as straightforward as possible.

In this blog we’ll be taking a look at the F62 error code displayed by Vaillant boilers, including -  what it means, what causes it and how it can be fixed. 

What is a Boiler Error Code?

An error code is exactly as it sounds, an alphanumeric code (F62) displayed upon a boiler's control screen or window, usually found at the toe or in the centre of the boiler.

Error (fault) codes are displayed by a boiler when it senses either a function or component is not operating soundly, causing sub-optimal performance and in rare cases, health risks.

Vaillant F62

The F62 error code on Vaillant boilers indicates a problem with the gas valve. Specifically, it means that the gas valve has failed to open during the ignition sequence. 

This can happen due to a variety of reasons, such as a fault with the gas valve itself, a problem with the wiring or connections to the gas valve, or a fault with other components in the ignition circuit.


The gas valve is responsible for regulating the flow of gas into a Vaillant boiler. When you require heating or hot water, the valve opens to allow gas to enter the boiler and ignite the burner. 

However, if the valve remains open when the boiler is not in use, it poses a significant risk of a gas leak, which can be very dangerous.

Fortunately, Vaillant boilers are designed to trigger a ‘lockout’ (shut down) in the event of a faulty gas valve. If you see the F62 fault code on your boiler, you should immediately turn off the gas supply and contact a Gas Safe Registered engineer to address the issue.

Several factors can cause a faulty gas valve, including:

PCB issues

a faulty PCB that sends incorrect signals to the valve can cause it to open and close at the wrong time, leading to gas flowing through when not required and no gas when you need it.

Intermittent connection

an intermittent connection between the PCB and the valve would result in the same problems as the communication between components would cause heating system issues.

Gas valve stuck

Your gas valve can become stuck due to wear and tear, this would result in the display of an F62.



As frustrating as it may seem, the F62 represents a serious fault with your boiler and it must be analysed and fixed by an expert, a Gas Safe registered engineer.

Should I get a New boiler?

If there is a fault with your boiler's PCB it can seriously hinder the performance of your boiler and it could be worthwhile getting a newer model.

Other issues can be fixed by a qualified engineer more easily, but the most effective way of avoiding an F62 is by replacing any old boilers with a modern, efficient boiler. Modern boilers have been meticulously designed and expertly crafted for not only peak performance, but also product longevity.

Even if your current boiler is an antiquated system or showing no signs of wear and tear it can still be a good idea to upgrade.


Here at iHeat we stock a range of premium boilers that can heat your home as well as save you money in the long run. We also work swiftly and accurately via online location assessments to make everything as simple as possible for you.

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Frequently Asked Questions

Why is my Vaillant boiler showing F62?

The F62 error code on a Vaillant boiler indicates an issue with the gas valve, which is failing to close properly, causing the boiler to stop operating.

How can I troubleshoot F62 error on a Vaillant boiler?

To troubleshoot an F62 error, check the boiler's gas supply and for any gas leaks. If all is well, the gas valve might be failing or misinstalled. A qualified Gas Safe engineer should be contacted to resolve the issue.

Is error F62 related to F61 in Vaillant boilers?

Yes, both F62 and F61 error codes are related to issues with the gas valve. F61 indicates a fault with the gas valve's operation, and F62 signifies the gas valve isn't closing properly.

What steps are needed to fix a Vaillant F62 error?

To fix an F62 error, switch off the boiler, disconnect it from the electricity supply, and contact a Gas Safe registered engineer. The engineer will inspect the gas valve and its connections, possibly replacing or adjusting the valve, and ensure the boiler functions correctly.

Are F62 errors similar to other Vaillant fault codes?

While F62 errors concern the gas valve, other Vaillant fault codes may refer to different boiler components. Each code helps diagnose and inform users of specific operational issues.

Do Vaillant Ecotec boilers commonly experience F62 error?

F62 errors can occur in Vaillant Ecotec boilers but aren't common. Regular servicing and maintenance by a Gas Safe engineer can help prevent and detect potential issues early, ensuring safe and efficient operation.

Stephen Day profile photo
Article by
Stephen Day | Co-founder
Gas Safe registered and FGAS certified engineer with over 20 years experience in the heating and cooling industry.