Replacing The Flow Sensor - Viessmann VITODENS 200-W Installation And Service Instructions Manual

Maintenance
(cont.)
20
10
8
6
4
2
1
0.8
0.6
0.4
10 30 50 70 90 110
Temperature in °C
Fig. 53 Sensor type: NTC 10 k

Replacing the flow sensor

Fig.54
Note
In the event of a fault, both sensors need to be
replaced.
1. Drain the boiler on the heating water side.
2. Pull leads from flow sensor
Ω
A
.
A
2. Check the sensor resistance and compare it with
the curve.
3. In the event of severe deviation replace the sensor.
Danger
The boiler water temperature sensors are
immersed in the heating water (risk of scald-
ing).
Drain the boiler before replacing the sensor.
3. Undo screws and remove faulty flow sensor
4. Install new flow sensor
screws.
Troubleshooting
.
A
and secure with the
A
93