Information On Replacing The Hmu Heat Management Unit And Bcu Burner Control Unit - Viessmann VITODENS 222-F Installation And Service Instructions Manual

Repairs
(cont.)
Flue gas temperature sensor
■
Flow temperature sensor
■
Cylinder temperature sensor
■
Outlet temperature sensor
■
Temperature sensor, low loss header
■
20
10
8
6
4
2
1
0.8
0.6
0.4
10 30 50 70 90 110
Temperature in °C
Sensor type: NTC 10 k
Ω
Fault during commissioning (fault F.416)
During commissioning, the control unit checks for cor-
rect placement of the flue gas temperature sensor. If
fault message F.416 is displayed:
1. Check whether the flue gas temperature sensor is
correctly installed (bayonet fitting). See previous
diagram.
2. If required, correct the position of the flue gas tem-
perature sensor.
3. Check the flue gas temperature sensor resistance.
See previous chapter. Replace faulty flue gas tem-
perature sensor if required.

Information on replacing the HMU heat management unit and BCU burner control unit

If the burner control unit (BCU) is being replaced, com-
missioning is carried out with the "Service assistant"
software tool.
Outside temperature sensor
■
200
100
80
60
40
20
10
8
6
-20 -10 0 10 20
Temperature in °C
Sensor type: NTC 10 k
Ω
4. Turn off the ON/OFF switch.
5. Turn the ON/OFF switch back on.
Restart the commissioning assistant.
6. Check for leaks on the flue gas side.
Note
If fault message F.416 continues to be displayed
although the flue gas temperature sensor has been
correctly positioned: Initial commissioning may result in
burner faults e.g. caused by air in the gas line. Elimi-
nate the fault and unlock the device.
Spare part installation instructions and
"www.service-assistent.info"
Troubleshooting
30
93