Viessmann Vitoflame 100 Service Instructions For Contractors page 32

Troubleshooting
Diagnosis
(cont.)
Fault Flash-
ing
code
red
Combustion fault 7 ×
through pulsation
7 ×
7 ×
7 ×
7 ×
7 ×
CO is formed or
burner is very
sooty
CO2 content too
low or O2 content
too high
Excessive flue gas
temperature
32
Cause
Excessive gas
throughput
Mixer assembly (stage
2) incorrectly adjusted
Air damper incorrectly
positioned
Combustion chamber
pressure is too high
Start gas volume too
large or too small
Incorrect flue draught
Air shortage or excess
Incorrect setting
Infiltrating air
Excessive gas
throughput
Boiler contaminated
Measures
Adjust the gas through-
put in accordance with
rated boiler output
Change the mixer as-
sembly adjustment
(see from page 48)
Correct the switch cam
adjustment at the air
damper motor (see
page 8)
Check the pressure in
the combustion cham-
ber; clean the boiler, if
required
Adjust start gas volume
or opening characteris-
tics (see page 13)
Check flue pipe (chim-
ney)
Adjust correctly. Check
the boiler room ventila-
tion.
Adjust the nozzle pres-
sure in accordance
with the type of gas
used. Correct air dam-
per setting.
Seal flue pipe at boiler
flue outlet. Re tighten
boiler door screws and
those on flue outlet
cover.
Match gas throughput
to the rated boiler out-
put
Clean boiler and cor-
rect burner settings