Opening The Control Unit Casing - Viessmann VITODENS 200-W Installation Instructions Manual

Gas connection
(cont.)
2. Carry out a tightness test.
Note
For the tightness test, use only suita-
ble and approved leak detecting
agents (EN 14291) and devices.
Leak detecting agents with unsuita-
ble constituents (e.g. nitrites, sul-
phides) can lead to material dam-
age.
Remove residues of the leak detect-
ing agent after testing.
!
Please note
Excessive test pressure may
damage the boiler and the gas
valve.
Max. test pressure 150 mbar.
Where higher pressure is
required for tightness tests,
separate the boiler and the
gas valves from the gas sup-
ply pipe (undo the fitting).

Opening the control unit casing

!
Please note
Electronic modules can be dam-
aged by electrostatic dis-
charges.
Before beginning work, touch
earthed objects, such as heating
or water pipes, to discharge static
loads.
3. Vent the gas line.
Conversion to other gas types:
Service instructions
11