Viessmann VITODENS 100-W Installation And Service Instructions Manual page 38

Troubleshooting
Fault messages on the display
Displayed System characteris-
fault code tics
51 No DHW heating
52 Burner blocked
58 No DHW heating
59 No DHW heating
5A Burner blocked
A9 Control mode without
Open Therm device
b0 Burner blocked
b8 Burner blocked
E3 Burner in a fault
state
E5 Burner blocked
F0 Burner blocked
F1 Burner in a fault
state
38
(cont.)
Cause
Short circuit, outlet
temperature sen-
sor
Short circuit, flow
sensor
Lead break, cylin-
der temperature
sensor
Lead break, outlet
temperature sen-
sor
Lead break, flow
sensor
Communication
fault Open Therm
device
Short circuit, flue
gas temperature
sensor
Lead break, flue
gas temperature
sensor
Fault in safety
chain
Internal fault
Internal fault
Max. flue gas tem-
perature exceeded
Measures
Check the sensor (see
page 47).
Check connections and
lead; replace sensor if
required.
Check the sensor (see
page 44).
Check the sensor (see
page 47).
Check connections and
lead; replace sensor if
required.
Check connections and
lead; replace Open Therm
device if required.
Check the sensor (see
page 48).
Check the sensor (see
page 48).
Check the temperature
limiter and connecting
leads (see page 45).
Check the control unit,
and replace if required.
Check the ionisation elec-
trode and cables.
Press "Reset" (see
page 40).
Replace control unit.
Check heating system fill
level. Check circulation
pump. Vent the system.
Press "Reset" (see
page 40).