Vaillant F22 Fault

Vaillant F22 Fault

The F22 error code on a Vaillant boiler is an indication of low water pressure in the system. This can happen for many reasons including, leaks in the heating system, bleeding radiators or regular decrease in pressure with time. This situation will lead to an inefficiently and unsafely performing boiler thus requiring a quick solution.
Causes of the F22 Error Code

Leaking System: There are small leaks anywhere within the heating system that gradually decreases water pressure.

Bleeding Radiators: After having bled radiators to get rid of trapped air, consequently, it takes out water from the system lowering its pressure.

Natural Pressure Loss: Time gradually lowers pressure slightly within a heating system.

Troubleshooting and Resolving the F22 Error Code

Visible Leaks Check: In any part of your heating system including radiator pipes and boilers should be checked whether there are visible signs of leakage. A leaking one should be repaired if noticed.

Boiler Repressurization: Majority of Vaillant boilers have filling loops which could be used to repressurize the tank. Usually, normal levels range between 1.0-1.5 bars as shown by the gauge on boiler’s display screen. Follow all safety instructions provided by the manufacturer while refilling your boiler tank.

Radiator Bleeding: Not bleeding radiators recently can equally cause this problem since you may have air locked inside them leading to changes in pressures. By bleeding these then you restore normal operating conditions back to your unit.

Resetting Your Boiler: Resetting your boiler after working on its pressure as suggested through manufacture guide helps clear off F22 error codes so that normal functioning resumes.

Pressure Monitoring: Just observe how constant your repressuring efforts could be by watching whether any drops occur again as indicated by a barometer reading device during this stage upon completion when there are no more leakages or faults detected within it.

Professional Help Required: If after repressuring your system, you are unable to locate the source of low pressure; pressure drops again shortly; and or you feel uncomfortable undertaking anything at all, then it is prudent that a Gas Safe registered engineer be contacted.


It mainly calls for refilling and checking for leakages in order to fix the Vaillant F22 error code. To ensure effective functioning of your boiler and avoid problems related to pressure, having your boiler serviced regularly is important. Consult an expert always when your boiler issues cause doubts in you.