The explanation of the Vaillant boiler F22 failure code

When you least expect it, boiler problems can leave you without hot water and turn off your central heating. Fortunately, contemporary Vaillant boilers use error codes to indicate a problem. These make troubleshooting simpler and give you a method to gauge the problem’s seriousness. One of the most popular web searches is for the F22 fault code for a Vaillant boiler. This article explains the significance of this code, what you might be able to do about it, and when to call a Gas Safe-registered engineer.

What does Vaillant error code F22 mean?

When there is insufficient water pressure for your boiler to fire up, an F22 error occurs. Because of this, if you see a Vaillant F22 fault code, your boiler is probably “locked out,” which means that neither your faucets nor your shower are producing hot water. Your radiators won’t warm up as planned, which is another thing you’ll notice.

In addition to this code, you might see a number flashing on your boiler’s display, like 0.3. This is the internal system pressure, which, depending on the model, should typically be approximately 1.5 bar. If you have a pressure gauge, you might also check it to confirm the issue.

Advice: Vaillant boiler types can have different suggested pressure levels. For this info, please see the boiler’s handbook.

Fault Code F22 for Vaillant

Why is the water pressure in my boiler so low?

There are various reasons why boilers can lose pressure. These include old age, piping leaks, a broken expansion vessel, or a broken pressure release valve. If you have recently bled your radiators, you can also experience pressure decreases. However, air entering the system is the primary cause of the majority of Vaillant boiler F22 failures. As a result, you might need to top up the pressure approximately every six months.

Keep in mind that this is a decline that happens gradually rather than suddenly. There is an underlying problem if you have a rapid decrease of pressure or need to top off the boiler’s pressure level every few weeks.

How can I fix my Vaillant boiler’s pressure problems?

If you are convinced that you can repressurize your boiler correctly and safely, you can try it. The valves linked to each end of the boiler’s filling loop must be turned in order to do this. Please keep in mind that you shouldn’t have to do this more than a couple of times per year in order to remove the F22 code and return your system to normal.

  • Verify that the code displayed on your display is F22.
  • Locate the two valves, which are often found beneath the boiler.
  • then carefully turn the left valve after rotating the right valve by 90 degrees.
  • Aim to see a rising pressure bar on the boiler’s display.
  • Close both valves when the pressure is between 1.2 and 1.5 bar.
  • If the F22 error continues to occur, your boiler may need to be reset.
  • It should just take a few seconds to complete this process. Once the pressure reaches the desired level, ideally no higher than 1.5 bar for a cold system, make sure to close both valves. As a result, you can anticipate your monitor to read closer to 2 bar once your boiler has fired up and increased the pressure. If it rises above 2.5 bar, the system might have been overpressurized.

Tip: Did you increase the pressure excessively? Not to worry! By bleeding your radiators and monitoring the boiler pressure after each one, you can lessen it. We offer instructions on how to bleed a radiator yourself, but if you’d rather have us do it, just let us know. We could also look for hidden problems with your boiler.

See an illustration of a filling loop below a combi boiler. Your filling loop may be connected to the pipework or attached to an external expansion vessel if you have a system or heat-only boiler. 

F22 fault code on Vaillant boiler

What if the F22 returns in a few of weeks?

The moment has come to call in a Gas Safe-registered professional if the code reappears shortly after increasing the pressure. If they discover the source of the issue, they can then offer the boiler repairs you require. They will examine the boiler for any broken components. The most likely problem, if your specialist can’t locate a defect with the boiler, is a leak.

We have qualified and prepared gas engineers who can find leaks. They can immediately begin the non-invasive detection process on hidden sections of your system if they are unable to locate a fault with your boiler or a leak on the exposed components of your central heating system. By doing this, a new appointment is avoided. Please be aware that the half-hour rate for our leak detection service is different from the rate for gas work.

Important! Never attempt to perform the repairs yourself. This might seriously harm your boiler and increase your risk of carbon monoxide poisoning. The work of Gas Safe heating professionals on heating systems is always done in compliance with HSE rules.

How can I keep my Vaillant boiler from displaying the F22 error code?

It’s challenging to take precautions against boiler problems because they might occur abruptly and for a variety of causes. This is true for all manufacturers and models. The best course of action is to stay current with your servicing schedule. Home insurance providers need an annual boiler service, and if you don’t get one, you risk losing your manufacturer’s warranty.

Did you realize ? Your gas usage could be reduced by up to 30% with annual servicing. Your engineer can make sure that the boiler is operating at the proper temperature and burning gas effectively. If not, they can adjust it to improve its performance.

Regardless of whether a Vaillant boiler issue is caused by insufficient water pressure, a loose connection, or a broken part, Aspect can get to the root of the issue. We can offer the specialized advice, installation, and maintenance work you’d anticipate from a Vaillant specialist since we are Vaillant Advance-approved installers. Whatever the fault code, we’ll immediately resolve the issue to ensure a comfortable, energy-efficient home all year long.


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