What Does The Vaillant Boiler Error Code F22 Mean?


Guscott Heating Services

vaillant boiler error code f22

Are you the proud owner of a Vaillant boiler?

As you may be aware, not every boiler is created equal. There are a myriad of problems that can, from time to time, stop your central heating system from firing up in the way you need it to.

The next in our Boiler Error Code series is hoping to provide you with some insight into the common Vaillant F22 error code so you can make an assessment on what to do next.

What is a Vaillant F22 Error Code and what does it mean?

The Vaillant F22 error code is a warning that your boiler has low water pressure. To address the issue and to get your boiler working normally again, you’ll need to increase the water pressure back to the correct level. As a rule, Vaillant boilers will only work when they have the right water pressure. If the water pressure drops too low, your boiler will indicate an F22 error code, causing the system to lock, with both your hot water and central heating subsequently no longer working.

But how do I know what the water pressure should be?

Fear not, this short guide is designed to help. The water pressure for your Vaillant boiler to function optimally should be about 1.5 on the boiler’s inbuilt pressure gauge. The boiler will continue to work if the pressure drops below this, but once it drops to 0.3 bar or less, the error code will appear and the boiler will stop functioning as a safety measure.

So, what are the causes?

With insufficient water pressure, a Vaillant boiler cannot ignite and therefore will not function in order to heat your water and your home. With that in mind, you need to pinpoint the cause of the problem in order to get your boiler up and running properly again.

Losing pressure is not typically something to worry about. Boilers always lose pressure with time but the progression is very gradual. However, if the pressure in your boiler has suddenly dropped, it typically indicates that there is a leak inside the system that must be addressed.

Based on our experience, we always recommend that you should never try to repair a leak in your Vaillant boiler yourself. This is a job that needs to be tackled by a Gas Safe heating engineer. If you detect a leak, which may be by a radiator, around the boiler itself, or anywhere close to the pipes in your home, our advice is to switch off your water supply as soon as possible. This is in order to mitigate any damage that running water may cause to your property.

A leak is one possibility (and likely the most common) but it isn’t always the answer. If you can’t spot a leak in your system, it’s possible that there is another cause of the F22 error code. For example, a component inside the boiler such as a pressure sensor, pump lead or the pump itself, could be defective. In this instance, we again recommend you give us a call in order for one of our expertly trained engineers to come take a look and begin working on a repair.

How is the Vaillant Boiler F22 fault addressed?

In order to resolve this error and get the boiler firing again, you need to increase the pressure. We recommend these steps as a starting point:

  • Switch off your boiler.
  • Wait for the boiler to cool.
  • Locate the filling loop – usually under the boiler. It looks like a metal hose with valves at both ends.
  • Turn the valves that enable water to enter into the boiler.
  • Keep an eye on the pressure gauge.
  • When the needle gets to the 1.5 bar mark, return the valves to their original position.
  • Give us a call, let us know the error code and we’ll get an engineer at your home as soon as possible.

We don’t recommend trying to fix the problem yourself. Boilers are complicated and the issues are often nuanced. The steps above are designed as a safety measure but we always recommend getting a Gas Safe professional, like those here at Guscott Heating Services, to come out to your home and take a look. More often than not, it will save you time and money in the long run.

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