Viessmann Vitovalor 300-P Installation And Service Instructions For Contractors page 132

Troubleshooting
Repairs (gas condensing module)
A
Fig. 107
20
10
8
6
4
2
1
0.8
0.6
0.4
10 30 50 70 90 110
Temperature in °C
Fig. 108 Sensor type: NTC 10 k
Fault "A3" during commissioning
During commissioning, the control unit checks whether
the flue gas temperature sensor is correctly positioned.
If the flue gas temperature sensor is not positioned
correctly, commissioning is cancelled and fault mes-
sage A3 is displayed.
132
(cont.)
Ω
1. Pull leads from flue gas temperature sensor
2. Check sensor resistance and compare it to the
curve.
3. In the event of severe deviation replace the sensor.
1. Check whether the flue gas temperature sensor is
correctly inserted. See previous diagram.
2. If necessary, correct the position of the flue gas
temperature sensor or replace faulty flue gas tem-
perature sensor.
.
A