65
Note
If fault message 416 continues to be displayed
although the flue gas temperature sensor is correctly
positioned: Initial commissioning may result in burner
faults e.g. caused by air in the gas line. Eliminate the
fault and reset the appliance.
Information on replacing the HBMU heat management unit
If replacing the HBMU heat management unit, the
"Vitoguide app" must be used.
See spare part installation instructions and inter-
net address:
Replacing the power cable
When replacing the power cable, only use the power
cable available as an individual part from Viessmann.
Replacing the HMI connecting cable
!
Please note
Incorrect routing of the cable can lead to heat
damage and impairment of the EMC properties.
For positioning and securing of the cable (fixing
point of the cable tie) see connecting cable
installation instructions.
Checking the fuse
2.
F1
4.
3.
1.
B
Fig. 31
1.
Turn off the ON/OFF switch
B
.
2.
Remove the programming unit.
3.
Pivot the HBMU heat management unit down.
4.
Remove cover
A
.
5.
Check fuse F1 (see connection and wiring dia-
gram).
Danger
Incorrect or improperly fitted fuses can lead
to an increased risk of fire.
■
Insert fuses without using any force. Posi-
tion fuses correctly.
■
Only use structurally identical types with
the specified response characteristics.
Troubleshooting
Repairs
(cont.)
6174240
Diagnosis