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How do I fix the F20 on my Vaillant boiler?


With everyday use, your Vaillant boiler may display different codes; some stand for errors, and some are warnings. An F20 code indicates your boiler is overheated and needs time to cool down and return to its normal function. Luckily, a Vaillant boiler has the safety feature of shutting down automatically when an error code like F20 appears. This safety feature leads to a lockout in the system, stopping it from further damage or any unexpected mishaps. This blog will help you answer the question how do I fix the F20 on my Vaillant boiler?

Also, it should never be ignored whenever you notice this error code in your boiler’s display. It would be best if you immediately shut down to ensure the boiler cools down, returns to its average temperature, and begins to function normally later on. On the contrary, have you ever wondered about what it would be life for other brands? For instance, you can check out our blog done for the Ideal Logic F1 fault code – everything you need to know

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We believe that your safety and the safety of your home is of utmost importance during a boiler service or any other gas appliance-related work. Our customer-first approach is what has allowed us to build up a stellar reputation over the last decade. The only way to ensure that your boiler or appliance is functioning efficiently and safely is with regular maintenance and professional servicing, which are usually carried out annually. There are a number of reasons to get a yearly service.


F20 Fault Code Vaillant Boiler

The F20 Fault code generally appears on the display when the boiler temperature exceeds 97 degrees Fahrenheit. The system automatically stops working whenever this fault code appears on your Vaillant boilers. This automatic cut-off often protects your homes from the worst scenarios resulting from extreme boilers heating. While using Vaillant boilers, you must have noticed that the system uses various codes to communicate the errors with you. Just like the human body has a unique language of communicating illness through symptoms, you can say these errors are symptoms of system failure. Similarly, F20 is a code that indicates overheating, and this overheating issue may be rooted in some faulty parts.

If you do not know boiler parts and their functions, you should reach out to a registered Gas Safety expert if the issue is not resolved even after allowing the boiler to cool. Still pondering and asking yourself, how do I fix the F20 on my Vaillant boiler? Worry not, as we’re not done yet. Keep reading. When these situations arise, and when you feel overwhelmed and want to get the support of a professional, then it really is the right thing to do. So, find out how you can benefit from a boiler repair London
service through us.

What Does F20 Mean On My Vaillant Boiler?

As mentioned earlier, the message behind the F20 fault code is apparent; it means overheating. This code is usually displayed on boilers used regularly for long hours. With regular use, all machines come across minor or significant faults, and so does a Vaillant boiler. Although overheating is a common issue and gets quickly resolved after allowing the boiler to cool down, it is always wise to look at its root cause. Sometimes, running the boiler for long hours is not the only reason behind the system lockout and display of the fault code.

Even if the boiler’s function returns to normal after cooling down, there may still be issues deep down. If not paid attention to on time, such minor problems may become major ones and disrupt the boiler’s function. Hence, instead of ignoring this issue or taking it lightly, you may want to be doubly sure that the system has no faults. Before we move on, we invite to check out our blog on types of boiler systems, should you ever feel the need to look into what boiler type would work best for you.

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What Causes F20 Fault on a Vaillant Boiler?

Common reasons behind the F20 fault code cause the boiler system to lock out. Before you contact a Gas Safety engineer, you can check if the issue lies with the following:

  • A faulty thermostat
  • A broken fan
  • Blockage in the pressure-relief valve
  • The kettling of a heat exchanger
  • The pump is dirty and clogged
  • Limescale has come closer to the thermistor
  • A leak in the pressure relief valve

Although recognizing these common issues is easy, the best advice is not to fix them yourself. Fixing these internal issues is the job of a registered Gas Safety engineer who can deal with problems with safety measures. With no prior knowledge of the boiler’s system, it can prove to be dangerous and cause further damage if you try to replace pipes or the broken fan. Hence, you should always trust a professional to solve such problems. We hope this blog enabled you to get an answer to your question – how do I fix the F20 on my Vaillant boiler?

Vaillant F20 Fault Code How to Fix?

Most of the time, when the problem is only overheating, it gets resolved after allowing the boiler to cool down and restart it. But what happens if this issue keeps on appearing again and again? Is this a serious issue? Is it possible to resolve this issue? If yes, how can you fix it? Honestly, fixing faults is the work of an expert, and before touching or fixing anything by yourself, you should always consult a Gas Safety expert.

When problems lie with the thermostat, pressure-relief valve, pump, and pipelines or heat exchangers, fixing them is not your cup of tea. For these issues, you have to trust a professional. An experienced professional is industry-trained and can help find the root cause behind F20 error codes. Their services shall ensure you do not meet these issues again shortly. If your boiler has become old, a Safety expert can also help you install new parts or repair old ones.