Viessmann VITODENS 300 WB3A, Service Instructions Manual

Page: 31 / 148

& 6.6 to 10.0 % for natural gas E
& 7.0 to 10.0 % for natural gas LL and
& approx. 10.0 % for LPG P.
Compare the actual CO
2
value with the above CO
2
value ranges for the indivi-
dual gas groups (check the gas group with your mains gas or LPG supplier).
If the actual CO
2
value deviates by more than 1 % for natural gas or 0.5 % for
LPG, proceed as follows:
& Check whether the correct gas restrictor has been installed.
& Check the balanced flue system for soundness, see page 17.
1. Connect a flue gas analyser at the
flue gas aperture
A
on the boiler
adaptor.
2. Open the gas shut-off valve, com-
mission the boiler and create a heat
demand.
3. Select the lower rated output.
Constant temperature control units:
& Press both keys
9
and
d
simul-
taneously, until the display shows
1.
Weather-compensated control
units:
& Press both keys
9
and
d
simul-
taneously until the display shows
"Relay test".
& With
a
/
b
in the display, select
"Basic load".
4. Check the CO
2
content. Should the
actual value deviate by more than
1 % from the above range, imple-
ment steps from page 15 (possibly
replace the burner).
5. Enter actual values into the service
report.
Further details regarding the individual steps
(cont.)
15
Initial start-up, inspection, maintenance
56
92
550
GB