66
Displayed fault
code
System characteristics
Cause
Measures
29
Regulates without flow tem-
perature sensor for low loss
header.
Lead break, low loss
header sensor
■
Check commissioning assistant
setting, low loss header.
■
Check flow temperature sensor,
low loss header.
■
Measure voltage at sensor input
on electronics module. Set value:
3.3 V
–
with sensor disconnected
30
Regulates without flow tem-
perature sensor for low loss
header.
Short circuit, low loss
header sensor
Check flow temperature sensor,
low loss header.
Measure voltage at sensor input on
electronics module. Set value:
3.3 V
–
with sensor disconnected
49
Burner in a fault state
Lead break, flue gas tem-
perature sensor
Check flue gas temperature sen-
sor.
Reset the appliance.
50
Burner in a fault state
Short circuit, flue gas tem-
perature sensor
Check flue gas temperature sen-
sor.
Reset the appliance.
57
Control mode without room
influence
Lead break, room temper-
ature sensor
■
Check commissioning setting of
remote control.
■
Check plug and cable of external
room temperature sensor, heat-
ing circuit.
■
If no external room temperature
sensor installed, replace Vitotrol
programming unit.
58
Control mode without room
influence
Short circuit, room tem-
perature sensor
Check plug and cable of external
room temperature sensor, heating
circuit.
If no external room temperature
sensor installed, replace Vitotrol
programming unit.
59
Burner blocked, boiler circuit
pump off. No central heating,
no DHW heating
Power supply, low voltage Check mains voltage.
If voltage is correct and the fault
occurs repeatedly, replace the fan
unit.
62
Burner in a fault state
High limit safety cut-out
has responded.
■
Check heating system fill level.
■
Check pre-charge pressure in di-
aphragm expansion vessel. Ad-
just to required system pressure.
■
Check whether flow rate is suffi-
cient (circulation pump).
■
Check function of 3-way diverter
valve. Vent the system.
Reset the appliance.
Troubleshooting
Fault messages
(cont.)
6167586
Diagnosis
