Checking The Diaphragm Expansion Vessel And System Pressure; Checking Electrical Connections For Tightness 25. Checking All Gas Equipment For Tightness At Operating Pressure; Flue Gas Emissions Test - Viessmann VITODENS 200-W Service Instructions Manual

Further details regarding the individual steps

Checking the diaphragm expansion vessel and system pressure

Note
Carry out this test on a cold system.
1. Drain the system, or close the cap
valve on the diaphragm expansion
vessel and reduce the pressure, until
the pressure gauge indicates "0".
2. If the pre-charge pressure of the dia-
phragm expansion vessel is lower
than the static system pressure, top
up with nitrogen until the pre-charge
pressure is raised by 0.1 to 0.2 bar.
Checking all gas equipment for tightness at operating pressure
Danger
Escaping gas leads to a risk of
explosion.
Check gas equipment for tight-
ness.

Flue gas emissions test

The electronic combustion control unit automatically ensures an optimum combustion
quality. Only the combustion values need to be checked during commissioning and
maintenance. For this, check the CO
electronic combustion control unit, see page 102.
Note
Operate the appliance with uncontaminated combustion air to prevent operating
faults and damage.
CO or O content
2 2
The CO content must be within the following ranges (upper and lower output):
2
Commissioning, inspection, maintenance
3. Top up with water until the filling pres-
sure of the cooled system is min.
1.0 bar and 0.1 to 0.2 bar higher than
the pre-charge pressure of the
expansion vessel.
Permiss. operating pressure: 3 bar
Note
For the tightness test, use only suitable
and approved leak detecting agents (EN
14291) and devices. Leak detecting
agents with unsuitable constituents (e.g.
nitrites, sulphides) can lead to material
damage.
Remove residues of the leak detecting
agent after testing.
or O content. For a function description of the
2 2
(cont.)
23