Viessmann VITOLIGNO 300-C Installation And Service Instructions Manual page 135

High limit safety cut-out
B A
Fig. 81
Sensors
Sensor type Pt1000:
■ Flow temperature sensor
■ Buffer temperature sensor
■ Return temperature sensor
■ Flue gas temperature sensor
Outside temperature sensor
■
Connection
See chapter "Connection and wiring diagram" from
page 184.
Checking the sensors
Flue gas temperature sensor
1.75
1.25
0.75
A 50
0
Temperature in °C
Fig. 82
Data point shown: Resistance of 1.1 k
A
perature of 25 °C
(cont.)
150 200
100
at a tem-
Ω
1. Move cover
A on the programming unit to the
right.
2. Press green button
B
out.
A quiet "click" will be audible. The high limit safety
cut-out has been reset.
3. Close cover on the programming unit.
A
4. Acknowledge excess temperature at the program-
ming unit with d .
Curve of the sensor from the extension kit for heating
circuit with mixer:
Extension kit installation instructions
250
Maintenance
of the high limit safety cut-
135