Checking The 15A And 15B Flue Gas Sensor; Checking The 3A And 3B Boiler Temperature Sensor - Viessmann Vitocrossal 200 CM2 500 Service Instructions Manual

Vitocrossal 200, CM2 400, 500 and 620 Service
Steps – Commissioning, Inspection and Maintenance
Temperature
3A sensor (NTC 10k )
Temperature
3B sensor (NTC 20k )
Temperature
Commissioning, Inspection, Maintenance
(continued)

Checking the 15A and 15B flue gas sensor

Viessmann NTC 10 kΩ (blue identification)
Note: The sensor is located on the flue gas collector and
the connecting plug is located at the burner control
unit.
Note: For sensor replacement see page 47.
Note: The flue gas temperature sensors are connected
directly to the burner control. The burner control
is factory set to open at 230°F (110°C). During
boiler operation the flue gas temperature sensor
sends a signal to the burner control and will disable
the burner operation when the flue gas temperature
reaches 230°F (110°C). The temperature switch
will reset once the temperature drops approximately
20°F (10°C) from the factory set point. Check the
burner control for fault F F1 on the display also
check the flue gas collector and/or vent system for
damage.

Checking the 3A and 3B boiler temperature sensor

Note: The sensor is located on the boiler supply
connection and the connecting plug is located
at the burner control unit.
Note: For sensor replacement see page 47.
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