Viessmann Vitotronic 100 GC1 Installation And Service Instructions Manual page 102

Troubleshooting – Vitotronic 300-K, MW1S
Faults displayed at the programming unit
Fault
System characteristics
code
7 7 7 7 0 0 0 0
Shunt pump constantly ON
With DHW heating: With DHW heating:
Mixing valve primary circuit closed, Mixing valve primary circuit closed,
7 7 7 7 8 8 8 8
no DHW heating
9 9 9 9 2 2 2 2
Control mode
Only solar control unit fault codes Only solar control unit fault codes
will be displayed will be displayed
9 9 9 9 3 3 3 3
9 9 9 9 4 4 4 4
9 9 9 9 a a a a
9 9 9 9 b b b b
9 9 9 9 c c c c
9 9 9 9 f f f f
A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A F F F F a a a a b b b b
Controlled operation, possibly DHW
tank cold
a a a a c c c c m m m m
Control mode
b b b b 1 1 1 1
b b b b 4 4 4 4
Emissions test mode
b b b b 5 5 5 5
Control mode
b b b b 6 6 6 6
Constant mode
b b b b a a a a
Mixing valve closed
102
(cont.)
Cause
Short circuit
Temperature sensor aJB
Open circuit
Temperature sensor aJB
Short circuit
Collector temperature sensor
Short circuit
Collector return temperature sensor
Short circuit
DHW tank temperature sensor
Open circuit
Collector temperature sensor
Open circuit
Collector return temperature sensor
Open circuit
DHW tank temperature sensor
Error
Solar control unit; displayed if an
error without fault code occurs at
solar control unit
DHW heating configuration error:
Coding 55 : 3 has been set, but
aJB not plugged-in
and/or
coding 4C : 1 and 4E : 1 not set
Return temperature control
configuration error:
Coding 0C : 1 has been set, but
aJA not plugged-in
and/or
coding 4E : 0 not set
Communication error
Programming unit
Internal electronics fault
Invalid hardware recognised
Communication error
Mixing valve extension Printed
Circuit Board
Remedy
Check temperature sensor
(see page 126), (see page 126),
Set coding 4b : 0, if no sensor Set coding 4b : 0, if no sensor
is connected
Check solar control unit sensor
Check solar control unit
Insert plug aJB and check coding
Insert plug aJA and check coding
Check connections and replace
programming unit if necessary
Check Printed Circuit Board and
replace if necessary replace if necessary
Check the control software circuit
board and confirm the coding address:
- Enter coding 2 (see page 151
for instructions).
- Change code 8A to 176.
- Confirm coding 92:18 4
Check Printed Circuit Board and
replace if necessary