Checking The Flue Gas Temperature Sensor; Replacing The Flue Gas Temperature Sensor - Viessmann Vitocrossal 200 CM2 186 Service Instruction

Commissioning, Inspection and Maintenance

Checking the Flue Gas Temperature Sensor

Flue temperature sensor
Boilers with a polypropylene flue gas collector are
supplied with a flue gas temperature sensor, which must
be installed.
Boilers with a stainless steel flue gas collector do not
have provisions for a sensor well but may connect an
optional flue gas temperature sensor in the venting
system. Contact your venting supplier.
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.

Replacing the Flue Gas Temperature Sensor

22
Vitocrossal 200 CM2 186 to 311 Service
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.
Temperature
1. Remove the rear boiler panels.
Refer to the Installation Instructions for details.
2. Remove spring clip from the sensor well and set aside.
3. Remove the flue gas temperature sensor from the
sensor well.
4. Disconnect sensor cable plugs 15A/15B.
5. Install new sensor.
Refer to the Installation Instructions for
installation details.
IMPORTANT
Careful not to damage the temperature probe or
capillaries during installation.