Viessmann VITODENS 100-W Installation And Service Instructions Manual page 45

Repairs
(cont.)
20
10
8
6
4
2
1
0.8
0.6
0.4
10 30 50 70 90 110
Temperature in °C
Checking the temperature limiter
2. Check the sensor resistance and
compare it with the curve.
3. In the case of severe deviation, drain
boiler on the heating water side and
replace the sensor.
If the burner control unit cannot be reset
after a fault shutdown, although the
boiler water temperature is below
approx. 95 °C, check the temperature
A
limiter.
1. Pull the leads from temperature lim-
iter A.
2. Check the continuity of the tempera-
ture limiter with a multimeter.
3. Remove the faulty temperature lim-
iter.
4. Install a new temperature limiter.
5. Press "Reset" at the control unit (see
page 42).
Troubleshooting
Danger
The boiler water temperature
sensor is immersed in the
heating water (risk of scald-
ing).
Drain the boiler before replac-
ing the sensor.
45