Viessmann VITODENS 111-W Installation And Service Instructions Manual page 31

Further details regarding the individual steps
Checking the CO
The Vitodens 111-W is factory-set for
natural gas. During commissioning or
maintenance, the CO
be measured at the boiler flue adaptor
test point to check the flue integrity. Sub-
ject to the Wobbe index, the CO
fluctuates between 7.4 % and 10.5 %.
CO of up to 500 ppm during start-up is
acceptable.
We recommend measuring O
value is unmistakable regarding lambda
(air/gas). The O content fluctuates
2
between 7.5 % and 3.2 %. The CO/CO
ratio has to be less than 0.004.
A
r r
content
2
and CO have to
2
content
2
as the
2
2
Commissioning, inspection, maintenance
(cont.)
If the actual CO or O
2
deviate from the stated range, check the
balanced flue systems for leaks. If flue
installation is OK, change the gas
valve.
Note
Operate the appliance with uncontami-
nated combustion air to prevent operat-
ing faults and damage.
01. Connect a flue gas analyser to flue
gas port A on the boiler flue con-
nection.
02. Start the boiler and check for
leaks.
Danger
Escaping gas leads to a risk
of explosion.
Check gas equipment for
tightness.
03. Turn rotary selector "tr" fully
clockwise, until the display shows
"SERV".
Within 2 s return the rotary selector
to the r.h. control range. The display
shows "A".
and CO values
2
31