Viessmann Vitodens 100 WB1A Installation And Service Instructions Manual page 52

Installation
Commissioning and testing
52
(cont.)
1. Close the gas shut-off valve.
2. Release the screw inside test nip-
ple "IN" A on the gas combination
valve , but do not remove, and con-
nect the pressure gauge.
3. Open the gas shut-off valve.
4. Check the static pressure; it should
be a max. 20 mbar +/- 1mbar.
5. Switch on mains voltage and start
up the boiler.
Note
During commissioning, the boiler
can enter a fault state because of
airlocks in the gas pipe.
To reset press "U" key. The ignition
procedure will then be repeated.
6. Check the inlet working pressure =
20 mbar.
&
Minimum working pressure = 12
mbar
&
Maximum working pressure = 20
mbar
Note
Use suitable test equipment, with a
resolution of at least 0.5 mbar, to
measure the supply pressure.
7. Shut down the boiler, close the gas
shut-off valve, remove the pressure
gauge, and close test nipple A
with the screw.