Fault Codes - Viessmann VITOTRONIC 200 Installation And Service Instructions Manual

Vitotronic 200, HO1B and 300-K, MW2C Installation/Service

Fault Codes

Fault codes
Displayed fault code System characteristics
10 Activates at 32°F (0°C) outdoor
temperature
18 Activates at 32°F (0°C) outdoor
temperature
19 Activates after 32°F (0°C)
outdoor temperature.
20 Standalone control unit without
supply temperature sensor
(possibly supply temperature
not high enough).
28 Standalone control unit without
supply temperature sensor
(possibly supply temperature not
high enough).
40 Mixing valve is being closed.
44 Mixing valve is being closed.
48 Mixing valve is being closed.
4C Mixing valve is being closed.
50 DHW tank primary pump "ON":
set DHW temperature
= set supply temperature
Priority control is cancelled.
or
With tank loading system:
DHW tank heating is started and
stopped by DHW tank temperature
sensor 2.
Cause
Short circuit, outdoor
temperature sensor
Lead break, outdoor
temperature sensor
Communication fault,
outdoor temperature sensor
RF
Short circuit, common
supply temperature
sensor/low loss header
temperature sensor
Lead break, common supply
temperature sensor/low
loss header temperature
sensor
Short circuit, supply
temperature sensor, heating
circuit with mixing valve
M2 (heating circuit 2)
Short circuit, supply
temperature sensor, heating
circuit with mixing valve
M3 (heating circuit 3)
Lead break, supply
temperature sensor, heating
circuit with mixing valve
M2 (heating circuit 2)
Lead break, supply
temperature sensor, heating
circuit with mixing valve
M3 (heating circuit 3)
Short circuit, DHW tank
temperature sensor 1
Troubleshooting
Measures
Check the outdoor
temperature sensor
(see page 105).
Check outdoor temperature
sensor (see page 105)
Check wireless connection
(place outdoor temperature
sensor RF close to the
wireless base station).
Log off outdoor temperature
sensor then log on again.
Replace if necessary (see
separate installation and
service instructions).
Check sensor
(see page 105).
Check sensor
(see page 105)
Check the supply
temperature sensor (see
page 105).
Check the supply
temperature sensor
(see page 105).
Check the supply
temperature sensor (see
page 105).
Check the supply
temperature sensor (see
page 105).
Check the DHW tank
temperature sensor
(see page 105).
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