How to pressurise the water system of a boiler

One of the repairs that tenants are expected to complete is to increase the pressure of the water system of the boiler.

Gas central heating systems use gas or oil to heat water than then runs through the radiators of the property to keep the ambient temperature comfortable.   This water system needs to have a minimum pressure, generally just above 1 bar.

Most central heating systems though, loose some water pressure with time.  The older, and the more you use the central heating, the more likely that increasing the pressure of the water system will be required.

Water pressure can be increased by simply opening a water valve, which is generally located within a couple of meters from the boiler.  In essence all you need to do is:

Locate the water pressure indicator (pressure would show a value below 1 bar)
Locate the water valve
Very slowly, open the water valve while looking at the pressure indicator.  The pressure will start increasing.
Close the water valve once the value of the pressure is around 1.5 bar.  Do not increase the pressure above 2 bar (very high water pressure will also make the heating system to work incorrectly).
Reset the boiler and switch it on.

Please watch these handy videos that will help you to complete this very simple task.

The basics, courtesy of Gregg Shirley, 

Boilers with internal key only, courtesy of Worcester Bosh Group

If you still have a question about your boiler after reading this article and watching the video, please contact us by leaving a comment below.
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