Sealed System pressure when
boiler is operating
OPERATING THE BOILER
PRESSURE GAUGE:
The pressure gauge indicates the boiler/heating system water pressure and has two pointers:
Red (external) pointer is set manually to indicate the normal system pressure (1 to 1.5 bar for sealed
systems, 0 to 0.5 bar for open vent systems).
Grey (internal) pointer shows the actual system pressure (on sealed systems the pressure will rise
when the boiler/system heats up from cold). Please check with your installer what type of system
you have.
On sealed systems the red pointer should be set to the normal operating pressure (1 to 1.5 bar) and
the grey pointer will fluctuate around this pressure depending on whether the system is hot or cold. If a
sealed system pressure drops below 1 bar the system should be repressurised to between 1 and 1.5
bar using the filling link (refer to page 7).
Regularly check that the pressure is maintained. If there is a persistent drop in pressure which has to
be adjusted regularly, or the pressure rises to more than 2.5 bar, the cause must be investigated.
Contact your installer or maintenance engineer for advice.
On open vent systems the pressure gauge is not used and the grey needle will remain at the bottom of
its scale. If the pressure rises to more than 1 bar please contact your installer for advice.
GREENSTAR HEATSLAVE EXTERNAL12/18 - 18/25 - 25/32
8 716 113 390e (03.2010)
6
USING YOUR
BOILER
