Fault Messages - Viessmann Vitotwin 300-W Installation And Service Instructions For Contractors

Fault messages

Explanatory notes on resetting (see
table below)
AR Automatic restart after the fault
has been remedied
ARP Automatic restart after the fault
has been remedied and mains
voltage disconnected
Fault mes- Cause
sage
"10: Outside Short circuit or lead break to
sensor" outside temperature sensor.
"20: Boiler Short circuit or lead break to
sensor 1" boiler temperature sensor.
"30: Flow Short circuit or lead break to
sensor 1" flow temperature sensor,
heating circuit 1.
"32: Flow Short circuit or lead break to
sensor 2" flow temperature sensor,
heating circuit 2.
"40: Return Short circuit or lead break to
sensor 1" return temperature sensor.
"50: DHW Short circuit or lead break to
sensor 1" cylinder temperature sensor
B3.
"60: Room Short circuit or lead break to
sensor 1" room thermostat, heating cir-
cuit 1.
"65: Room Short circuit or lead break to
sensor 2" room temperature sensor,
heating circuit 2.
"68: Room Short circuit or lead break to
sensor 3" room temperature sensor,
heating circuit 3.
"70: Buffer Short circuit or lead break to
sensor 1" buffer temperature sensor.
"71: Buffer
sensor 2"
"72: Buffer
sensor 3"
UR
Press
SR Service reset (see page 122)
NRP No restart possible, replace PCB
Remedy
Check outside temperature
sensor (see page 139)
Check the boiler water tem-
perature sensor (see
page 141)
Check flow temperature sen-
sor (see page 146)
Check the return tempera-
ture sensor (see page 143)
Check the cylinder tempera-
ture sensor (see page 140)
Check room thermostat and
connecting cable.
Check buffer temperature
sensor (see page 140)
Troubleshooting
Re-
set-
ting
AR
123