Offering a wide range of boilers and having a presence in 20 countries, Vaillant is one of the popular names in the heating and hot water domain. The Vaillant boilers are sturdy and reliable. However, even the best ones can go through some issues.
The F22 is one of the most common fault codes you may encounter while using the Vaillant boilers. It refers to low pressure in the boiler system, resulting in inadequate heating and cold-water supply.
Whether you are not able to find the underlying cause or the correct solution to solve the issue, then you have landed at the right place. In this guide, you will learn everything about the F22 fault.
What Exactly Is A Vaillant Boiler F22 Fault?
Ideal boiler pressure is crucial for better performance and smooth functioning. The optimum pressure is maintained through the right amount of water and air inside it. Any proportion change can prevent the boiler from maintaining the optimum pressure.
F22 fault in a Vaillant boiler is one of its most common issues. It refers to low pressure in the boiler due to an insufficient amount of water in it. The boiler will go into the lockout state and will stop working so that there is no further damage to it.
Once the issue is resolved, the boiler will return to its normal state, and there will be no fault code on the display screen.
Is F22 A Fatal Error For The Boiler?
No, F22 is not a dangerous error for your boiler, and you don’t have to replace your boiler to resolve it. The fault code refers to the low amount of water in the boiler, causing low pressure that makes it inadequate to function normally.
You need to resolve the underlying issue causing the fault to resume the boiler’s normal functioning. Remember, the boiler will not work correctly until the issue causing the F22 fault is resolved, and the boiler is reset.
Causes Of A Vaillant Boiler F22 Fault
With the F22 fault code on your Vaillant boiler screen, your boiler will stop working. You must repressurise the boiler to get it back to its normal state. Several reasons can cause the low water pressure in the boiler. It can be accidental, or your boiler can age out.
In this section, you will get familiar with all the possible reasons that can lead to the F22 fault code on your boiler screen. Let us dive into the list.
1. Ageing
When the boiler ages above 10+ years, it might start malfunctioning. It may have gradually lost the pressure over time, and you will have to repressurise it for normal functioning.
2. Leakage
If the pressure of the boiler goes through a sudden change in pressure, then it is highly probable that the main culprit is a leak in the system. Tiny pinholes in the boiler compartment, valves, and pipework can cause leakage and low pressure.
Moreover, the sealant in the joints and bends can lose its efficacy, and the water can drip out, causing low pressure and finally leading to the F22 fault.
3. Faulty Boiler Component
With time, there may be some component malfunctioning that can cause low pressure in the boiler. The pump can stop working, or the pressure sensor can stop signalling the correct pressure reading to the computer inside the boiler.
These scenarios can also lead to low pressure, and you may encounter an F22 fault with your Vaillant boiler.
4. Excessive Radiator Bleeding
While bleeding the radiators, you may accidentally let more water out of the system, which can cause low pressure in the boiler. You may forget to tighten the cap properly after the process, which can gradually lead to water loss and low pressure in the boiler system.
In both these cases, the boiler will have inadequate pressure to work and show the code on the display screen.
Can Fixing Vaillant Boiler F22 Fault Be A DIY Project?
Yes, in some cases, you can fix the F22 fault, but it is advised that you call a professional if you cannot find the underlying cause of the issue. Here are some scenarios where you can deal with the issue yourself.
- The boiler has low pressure over time and needs a top-up.
- You may have accidentally left a tap loose, which causes the low pressure.
- You only need to repressurise the boiler to regain the ideal pressure.
If you wish to deal with the issue yourself, here is a video link to understand the whole process. However, if you suspect that the issue is something other than the ones mentioned above, you need to call a professional for help.
Steps To Mitigate The Vaillant Boiler F22 Fault
There are some simple steps to inspect the problem and take the required course of action to resolve the F22 issue. In this step-by-step guide, you will get all the necessary details to find the issues and fix them.
Examine The Boiler Pressure
The first thing that you need to do is to look for boiler pressure. If the boiler pressure is near 1.5 bar and the display is still showing the F22 code, then you can be pretty sure that the pressure sensor is faulty.
You need to replace the pressure sensor to resolve the issue and go back to the normal functioning of the boiler. It is advised to call an engineer to replace the part rather than dealing with it yourself.
However, if the boiler pressure is less than 1.0 bar and further dips, then you need to check the system for any leak. So, let us move to the next step for all the details.
Leakage Checking
Leakage in any boiler component and pipework can allow water to drip out and lower the overall pressure. Commonly, the bends and joints are the most vulnerable parts of the whole system and develop tiny pinholes and cracks due to ageing and rusting. Water seeps out of these cracks and causes the boiler to deviate from its ideal pressure.
Besides this, the boiler compartment, expansion vessel, pressure valves, and other components can develop cracks over time and lead to low pressure in the boiler. To find the leak, you need to examine the whole system, including the pipework, thoroughly.
Calling a professional to check everything is recommended as it will save you a lot of time and effort. Moreover, the professional can securely access and seal all the damaged sites. If any component needs replacement, the professional will guide you properly.
After all the repairs and replacement, you must repressurise the boiler for normal functioning.
Repressurise The Boiler
You can repressurise the boiler system yourself. There are two ways to normalise the pressure of the boiler system, namely the internal filling loop and the external filling loop.
The internal filling loop is part of the installed system and is generally found beneath the boiler. The external filling loop is a grey-coloured mesh that you need to fix to the filling taps before repressurising the boiler. Let us get into the detailed steps of both methods.
Internal Filling Loop
- First, press the radiator button twice to check the current boiler pressure.
- Now, find the internal filling loop. It will be present beneath the boiler.
- You will see two grey-coloured taps. These taps control the flow of water.
- Turn the first tap (right-handed tap) to open it completely. Now turn the second tap (left-handed tap) slightly. You will hear a hissing sound. This means that the water is flowing into the boiler.
- Keep an eye on the display and close the tap once you reach the desired pressure.
- Close the other tap, and you will see the F22 code will disappear from the screen.
External Filling Loop
- First, you need to connect the external filling loop to the filling taps. Generally, you find the filling taps below the boiler itself.
- After connecting the filling loop, open the main water supply tap.
- Now, turn the second filling tap slightly so the water can move into the boiler compartment. The water flow is indicated by a hissing sound.
- Check the pressure on the display screen and turn off the tap once you reach the desired pressure. Also, close the main water supply tap.
- All done, you will display is not showing the F22 code.
- Don’t forget to remove the external filling loop. Ensure that the taps are closed appropriately, so no water seeps out.
Reset The Boiler
Once you have repressurised the boiler, you need to reset it. Press the reset button and hold it for 10 seconds. All done. Your boiler will resume normal functioning.
If you need help resetting your boiler, you can follow this link.
Other Common Vaillant Fault Codes
Besides the F22 fault, you may encounter several other fault codes with your Vaillant boiler. Moreover, if you are not able to resolve the F22 fault with the remedies mentioned above, then there may be some other issue with the boiler, which can be a lot more confusing. You can follow this link to learn more about the other codes and get the required help.
Final Words
F22 fault simply means low water quantity in the boiler, causing pressure deviation from the ideal reading for the boiler to work normally. Here, in this article, you will get familiar with the different causes that lead to the F22 fault. Once you know the main culprit, you can take the required course of action to tackle the issue.
