Viessmann VITODENS 100-W Installation And Service Instructions Manual page 64

Troubleshooting
Repairs
(cont.)
2. Disconnect wires 7 and 8 from terminal 4.
3. Check the sensor resistance. Compare the resist-
ance with the value for the current temperature
from the following diagram.
If the results are very different from the curve
(> 10 %), disconnect the wires from the sensor.
Repeat the test directly on the sensor.
Check the on-site lead. 2-core lead, length
up to 35 m with a cross-section of 1.5 mm
Depending on the test result, replace the lead or
the outside temperature sensor.
Flue gas temperature sensor
1. Check the lead and plug of flue gas temperature
sensor .
C
2. Disconnect leads, flue gas temperature sensor
3. Rotate sensor (anti-clockwise) by
it (bayonet fitting).
Flue gas temperature sensor
■
Flow temperature sensor
■
Outlet temperature sensor
■
20
10
8
6
4
2
1
0.8
0.6
0.4
10 30 50
Temperature in °C
Sensor type: NTC 10 k
Ω
Fault during commissioning (fault message 416)
During commissioning, the control unit checks for cor-
rect placement of the flue gas temperature sensor. If
fault message 416 is displayed:
1. Check whether the flue gas temperature sensor is
correctly installed (bayonet fitting). See previous
diagram.
2. If required, correct the position of the flue gas tem-
perature sensor.
64
2
turn to remove
¼
70 90 110
4. Check the sensor resistance. Compare the resist-
ance with the value for the currently recorded tem-
perature from the following diagram.
In the event of severe deviation (> 10 %), replace
the sensor.
5. Rotate sensor (clockwise) by
Danger
Escaping flue gas can cause poisoning.
When restarting, check for leaks on the flue
gas side.
6. Reconnect leads, flue gas temperature sensor
7. If the permissible flue gas temperature has been
exceeded, the flue gas temperature sensor locks
out the appliance. Reset the burner on the pro-
gramming unit once the flue system has cooled
C .
down.
Outside temperature sensor
■
200
100
80
60
40
20
10
8
6
-20 -10 0
Temperature in °C
Sensor type: NTC 10 k
3. Check the flue gas temperature sensor resistance.
See previous chapter. Replace faulty flue gas tem-
perature sensor if required.
4. Turn off the ON/OFF switch.
5. Turn the ON/OFF switch back on.
Restart the commissioning assistant.
6. Check for leaks on the flue gas side.
turn to install it.
¼
10 20 30
Ω
C .