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32
A
1.
Check the pre-charge pressure of the
diaphragm expansion vessel.
2.
Close the gas shut-off valve.
3.
Fill the heating system via boiler drain
& fill valve
A
. System pressure
> 1.0 bar (0.1 MPa).
4.
Close boiler drain & fill valve
A
.
Venting the boiler by flushing
A
B
1.
Close the shut-off valves on the heat-
ing water side.
2.
Connect the drain hose to boiler drain
& fill valve
B
.
3.
Open valves
A
and
B
. Vent under
mains pressure until no more air
noise can be heard.
4.
Close taps
A
and
B
; open the shut-
off valves on the heating water side.
Commissioning, inspection, maintenance
Further details regarding the individual steps
(cont.)
5585 174 GB