F22 Fault Code Valliant Boiler: Meaning & How to Fix

A woman onthe phone looking at a broken boiler

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August 25, 2023

If you and your family are suddenly left without any hot water and heating in your property, then check out your boiler. Valliant boilers are made to identify the problem and highlight it. It does this by displaying an error code. Match this with your Valliant boiler guidance book and you’ll be one step closer to identifying the issue.

One of the most commonly seen codes to be displayed is the f22. On the surface that probably means nothing to you. So, read on and we will explain the f22 on a boiler meaning further in this article:

The Meaning of an F22 Fault Code

The f22 fault code on a Valliant boiler means that your water pressure is too low.

You might also notice a number, such as 0.3 flashing up on your boiler’s display. This is the level of pressure that your boiler is currently sitting at. To work properly the water pressure in a Valliant boiler should be sitting at around 1.5.

Because the boiler can only work when it’s at the correct water pressure, it will ‘lock out’ for safety. In other words, it switches itself off – hence the reason you have no hot water and your central heating isn’t working. In fact, they won’t work again until the fault is rectified.

Possible Cause of an F22 Fault Code

There are a handful of reasons why your boiler might be losing water pressure.

  • There could be a leak in the pipes connecting the boiler to your water system. This may be down to the fact that your water system is so old one of the pipes has corroded.
  • It could be down to the fact that the boiler’s pressure release valve itself isn’t working.
  • there may be an issue with one of the pumps inside the boiler.
  • Bleeding your radiators can be another reason for low water pressure, although this usually rectifies itself after a short time.

By far the main reason for low water pressure though is when air seeps into the system. This can happen gradually and, because of this, it’s always a good idea to top the pressure up now and again. It’s not an emergency though, like the other reasons we’ve mentioned here. In fact, you should only need to top up the pressure twice a year, if that. It’s usually something a Gas Safe engineer will do at the boiler’s annual service.

How to Fix Your Boiler

If the cause of low water pressure is simply the gradual build-up of air then you may be able to fix this yourself.

  1. Turn the valves at the end of the boiler’s filling loop (under the boiler). Do the right valve first. Turn it to 90 degrees and then repeat the same process with the left valve.
  2. You should then see the water pressure sensor bar begin to rise. Once the bar reaches a mark between 1.2 and 1.5 you can ‘lock’ both valves into place.
  3. Reset your boiler and you shouldn’t be able to see the f22 code anymore.

Note that if the bar reaches 2.5 then you’ve gone to the other extreme and made the water pressure too high.

Preventing the F22 Error Code

The best way to prevent the F22 error code from appearing once again is to have your boiler serviced regularly – at least once a year.

It’s a good idea to check the water pressure yourself now and again and carry out the above manoeuvre every six months to keep it at the preferred water pressure – especially if the bar is about to fall into the ‘low water pressure’ zone due to insufficient water in the boiler.

The benefits of having your boiler serviced on an annual basis are far greater than ensuring your water pressure isn’t too low (although, as we know this is important).

Another good reason for an annual service is that setting the boiler to the correct temperature means it burns more efficiently; to the extent it may cut your gas bill by around one-third.

What to do if Comes Back

If, after a couple of weeks or so, the F22 error code returns on your boiler’s display then it’s essential that you call in a Gas Safe engineer at this point.

That’s because there is obviously something wrong with the boiler system.

Whether it’s a burst pipe, faulty pressure gauge etc. there’s only one way to fix the faulty boiler pressure – and that’s to call in a professional. They can find the source of the problem and, if it needs parts, have the equipment to fix it.

If it’s a leaky pipe in your property’s water system, then they can locate and replace that too.

Hiring a Professional

It really doesn’t make sense to carry out boiler repairs yourself – unless you are qualified Gas Safe heating engineer, that is!

Otherwise, if you don’t know what you are doing then you can certainly cause a lot of damage to the boiler and render any insurance policy invalid.

Not only that but it could put you and your entire family in danger. For starters, it increases the risk of carbon monoxide poisoning.

To find a Gas Safe heating engineer you can request a curated list of expert and positively-rated professionals in your area on The Page.

Let The Page curate you a free bespoke shortlist of tradespeople suited to you and your job.

You can also look up review sites and the professional Gas Safe register. Other trade bodies can be helpful for finding engineers near you but so can your neighbours, friends or colleagues who have also needed to locate a heating engineer at short notice.

Various online review sites will also have a list of Gas Safe heating engineers but there is no telling whether or not the reviews are real.

Another option is to look at social media, such as Facebook community pages for your particular town or city.


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