Viessmann Vitocrossal 200 Service Instructions For Contractors page 34

Burner control unit
Burner control unit VUC 310
3. S "6" is displayed under Status.
4. until "0" is shown under Service.
5. S "1" is shown under Status and "dEL" under Serv-
ice.
Manual operation and service display
To call up the service display and for manual operation
the burner must be running. The service display shows
the current modulation level in %.
Press the following keys:
1. /S simultaneously for longer than 2 s.
The burner changes to manual mode and a
"P" will be shown under Status. The current
modulation level will flash under Service.
34
(cont.)
6. S to confirm. If reset successfully, "1" is shown
7. S to change to the operating display.
2.
3.
4. /S simultaneously for longer than 2 s.
under Service; if it failed, "0" is shown.
for the lower heating output, until "0" is shown
under Service.
for the upper heating output, until "100" is
shown under Service.
The burner returns to modulating mode.