Troubleshooting Fault Display; Fault Memory; Fault Codes; General Process Errors - Viessmann VITOCROSSAL CRU 800 kW Service Instructions Manual

Troubleshooting
Fault display
If the burner control unit switches to a fault state, the
fault display is automatically activated. The most
recent fault is then displayed. The fault LED is also illu-
minated in the case of a non-lockout fault, or flashes
together with the fault code in the case of a lockout
fault.
Status Service
Fig. 25

Fault memory

The 10 most recent faults are saved and can be called
up. The most recent fault code is shown first, followed
by the preceding codes. If no key is pressed within
20 s the fault memory display terminates automatically.
Note
If the burner repeatedly starts up due to a non-lockout
fault without displaying a fault code, the fault memory
may give an indication of the cause.
Call up the fault codes:
1. S longer than 2 s, " " flashes.
2. until "4" is shown under Service.
3. S "4" is displayed under Status.
4. / to scroll through the fault memory display.
Service Description
1 Fault codes display
2 Detailed fault codes
3 Clear fault memory.

Fault codes

General process errors

Fault display on the display and programming unit on the burner
Note
Carry out measures in the order described.
All fault messages are saved to the fault memory and
the last 10 can be called up.
38
Fault code of the most recent fault, see table from
A
page.
1. Remedy the fault. For fault codes and measures,
see the following chapter. Carry out measures in
the indicated order.
2. Hold down reset button R for longer than 0.5 s.
The operating display appears again. The burner
control unit is reset.
5. S the selected fault memory display is shown
under Status.
6. / to scroll through the fault codes.
Clear the fault memory from the operating display:
1. S longer than 2 s, " " flashes.
2. until "4" is shown under Service.
3. S "4" is displayed under Status.
4. until "3" is shown under Service.
5. S "1" is shown under Status and "dEL" under Serv-
ice.
6. S to confirm the deletion. If deleted successfully,
"1" is shown under Service; if it failed, "0" is
shown.
7. S to change to the operating display.