The heating system's pressure is low, how do I re-fill the system?

When the heating system is cool, the pressure should be between 1 and 1.5 bar on the pressure gauge (the indicator needle would usually be in the green section).

If pressure is below 0.5 bar (or in the red section), water has been lost from the system and must be replaced.

Your system will have either an internal filling key or an external filling hose (sometimes called a loop).

The video below demonstrates how to repressurise a heating system using an internal filling key.

The video below demonstrates how to repressurise a heating system using an external filling hose.

The following links tell you how to repressurise your heating system by adding more water to it.

Repressurise a standard efficiency Worcester CDi gas combi boiler

Repressurise a Worcester gas condensing combi boiler or non-condensing i Junior or Si boiler

Repressurise heating system using an external filling hose

Please note

If you are constantly losing pressure from your heating system you may need to consult a heating installer.

Find out what to do if your heating system is constantly losing pressure