Operating instructions

Venting the boiler
1. Close t he shut-off valves on the
heating water side.
2. Connect the drain hose on valve A
with a drain outlet.
3. Open valve A andfillvalveinthe
heating return, and vent at mains
pressure, until no sound of escap-
ingaircanbeheardanymore.
4. Close val ve A and fill valve in the
heating return, and open the pri-
mary shut-off valves.
Venting the heating system
1. Close the gas shut-off v alve and
start the control unit.
2. Activate the venting program via
coding addr ess 2F:1.
Note
To call up code 1 and for setting the
coding addr ess, see page 39 .
For function and sequence of the
venting program, see page 104.
Whilst venting i s in progress, the
display shows EL (con stant tem-
perature control unit) or Venting
(weather-compensated control
unit).
3. Check the system pressure.
Further details regarding the individual steps (cont.)
8
Initial start-up, inspection, maintenance
5692 548 GB