Viessmann VITODENS 200-W Installation And Service Instructions Manual page 99

Fault messages
(cont.)
Displayed fault System characteristics
code
84 Burner in a fault state
85 Burner in a fault state
90 Control mode
91 Control mode
92 No solar DHW heating
93 Control mode
94 No solar DHW heating
95 Burner blocked
Cause
CO limit within appliance
exceeded
Gas supply insufficient
during calibration
Short circuit, temperature
sensor
/
Short circuit, temperature
sensor
aÖ
Short circuit, collector
temperature sensor
Short circuit, collector re-
turn temperature sensor
Short circuit, cylinder tem-
perature sensor
CO limit exceeded
Troubleshooting
Measures
Check entire flue gas path for the
following:
Flue gas recirculation
■
Leaks
■
Flue gas back pressure caused
■
by water pocket (if flue system
fall is insufficient)
Constrictions
■
Blockages
■
Repair flue system if necessary.
Press reset button R.
Test static gas pressure and gas
flow pressure.
Check that on-site gas line and gas
flow switch are correctly sized.
Visually inspect gas train inlet and
strainer on the inlet side for con-
tamination.
Note
Contamination from a brazed gas
line, for example, can block up the
gas train strainer on the inlet side.
Press reset button R.
Check sensor on the solar con-
/
trol module.
Check sensor aÖ on the solar con-
trol module.
Check temperature sensor
the solar control module or the
sensor on the Vitosolic.
Check the temperature sensor at
terminal S3 on the Vitosolic 100.
Check temperature sensor
the solar control module or the
sensor on the Vitosolic.
Danger
An increased concentration
of carbon monoxide can
cause potentially fatal car-
bon monoxide poisoning.
Observe the safety instruc-
tions at the beginning of this
manual.
Determine the cause of the in-
creased CO level. Remedy the
fault.
Press Test on the CO limiter. The
alarm is switched off.
The burner starts again once the
CO level is below the CO limit.
& on
on
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