Check Outdoor Temperature Sensor - Viessmann VITODENS 100-W WB1B Series Installation And Service Instructions Manual

Troubleshooting
Correction

Check outdoor temperature sensor

Fig. 71
Temperature
68
1. Disconnect cables from outdoor
sensor.
2. Measure resistance of the outdoor
sensor and compare with
resistance / outdoor sensor curve
shown below.
3. If the value measured differs
significantly, replace the sensor.
In weather-compensated mode
(optional), the boiler water
temperature is regulated subject to the
outside temperature.
Frost protection function
Built-in automatic frost protection
allows the boiler to be shut off for
an extended period of time while
protecting it against freeze-up. Frost
protection is continually active. The
burner is switched ON when the boiler
water temperature reaches 41º F /
5º C and is switched OFF again when
the boiler water temperature reaches
at least 59º F / 15º C (but not more
than 68º F / 20º C).
For details on the control,
please refer to the Vitodens
100-W Operating
Instructions.