Viessmann VITODENS 300 WB3A, Service Instructions Manual

Page: 91 / 148

4.
E
in the display indicates that the
burner control unit is locked out.
After the fault has been removed,
acknowledge by pressing reset
E
.
Fault display design
A
Fault symbol
B
Plain text fault display (only for
weather-compensated control
units)
C
Fault number
D
Fault code
Plain text fault display
& Burner control unit
& Outside temperature sensor
& Flow sensor
& Boiler sensor
& Mixed flow sensor
& DHW cylinder sensor
& Flue gas sensor
& DHW outlet sensor
& Room temperature sensor
& Collector sensor
& Solar DHW sensor
& Remote control
1. Calling up acknowledged fault
messages
Press
d
for approx. 3 seconds.
The fault will then be displayed.
2. Select the acknowledged fault
with
a
or
b
.
Checking and acknowledging faults
Weather-compensated control units
Red fault indicator
U
flashes for all
faults.
A fault message code flashes in the
programming unit display when a fault
message is issued.
Any fault codes present may be called
up with
a
or
b
.
Call up current fault codes
(cont.)
75
Troubleshooting
56
92
550
GB