Open Systems; Sealed Systems - Buderus SB735 Series Operating Instructions Manual

7 System maintenance
Systems are generally designated as open or sealed
systems. Open systems are now rarely installed.
Therefore, a sealed system is used as an example of
how you can check the water pressure.
The specialist will have carried out all initial settings
during commissioning.

7.2.2 Open systems

On open systems the pressure gauge needle (Fig. 4,
item 1) must be within the red range (Fig. 4, item 3).

7.2.3 Sealed systems

On sealed systems the pressure gauge needle (Fig. 5,
item 2) must be within the green range (Fig. 5, item 3).
Set the red needle (Fig. 5, item 1) on the pressure
gauge to the required system pressure.
Check the system water pressure.
SYSTEM DAMAGE
through frequent re-filling.
CAUTION!
The system may be damaged, depending
on water quality, by corrosion or scaling, if
you frequently need to re-fill your system
with make-up water.
Ensure that your heating system is
adequately vented.
Check the heating system for leaks and
the function of the expansion vessel.
The water pressure in the system is too low, if the
pressure gauge needle falls below (Fig. 5, item 2)
the green range (Fig. 5, item 3). Re-fill the heating
system with make-up water (see Chapter 3 "Using
correct fill and make-up water", page 7).
Fill make-up water through the fill cock in the heating
system pipework (return).
Vent the heating system.
Re-check the water pressure.
We reserve the right to make any changes due to technical modifications.
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Operating instructions condensing gas boiler Logano plus SB735 • Issue 10/2003
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Fig. 4 Pressure gauge for open systems
Item 1: Pressure gauge needle
Item 2: Green needle
Item 3: Red marking
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Fig. 5 Pressure gauge for sealed systems (in bars)
Item 1: Red needle
Item 2: Pressure gauge needle
Item 3: Green marking
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
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