Viessmann VITOTRONIC 100 GC1 Installation And Service Instructions Manual page 101

Diagnosis
(continued)
Faults with fault display on the programming unit (continued)
Fault
Behaviour of system
code in
display
30
Burner is switched on and off by
the adjustable high limit
38
Burner is switched on and off by
the adjustable high limit
50 DHW pump ON:
set-point boiler temperature =
set-point DHW tank temperature,
priority controls are cancelled
or
In conjunction with DHW heating:
Tank heating is switched on and off
by Tank temperature sensor 2
51
In conjunction with DHW heating:
Tank heating is switched on and off
by Tank temperature sensor 1
58 DHW pump ON:
set-point boiler temperature =
set-point DHW tank temperature,
priority controls are cancelled
or
In conjunction with DHW heating:
Tank heating is switched on and off
by Tank temperature sensor 2
59 In conjunction with DHW heating:
Tank heating is switched on and off
by DHW tank temperature sensor 1
60
No output reduction
Return control open
Boiler with maximum temperature
68 No output reduction
Return control open
Boiler with maximum temperature
70 70
Shunt pump ON continuously
In conjunction with DHW heating:
Mixing valve of primary circuit
closed, no domestic hot water
heating
78 78
Shunt pump ON continuously
In conjunction with DHW heating:
Mixing valve of primary circuit
closed, no domestic hot water
heating
Cause of fault
Short circuit
Boiler temperature sensor
Open circuit
Boiler temperature sensor
Short circuit
DHW tank temperature sensor 1
Short circuit
DHW tank temperature sensor 2
Open circuit
DHW tank temperature sensor 1
Open circuit
DHW tank temperature sensor 2
Short circuit
Temperature sensor aJA
Open circuit
Temperature sensor aJA
Short circuit Short circuit
Temperature sensor aJB Temperature sensor aJB
Open circuit Open circuit
Temperature sensor aJB Temperature sensor aJB
Troubleshooting
Action
Check boiler temperature sensor (see
page 50)
Check boiler temperature sensor (see
page 50)
Check DHW tank temperature sensor
(see page 51)
Check DHW tank temperature sensor
(see page 51)
Check DHW tank temperature sensor
(see page 51)
Check DHW tank temperature sensor
(see page 51)
Check temperature sensor
(see page 52)
Check temperature sensor
(see page 52)
Check temperature sensor Check temperature sensor
(see page 52) (see page 52)
Check temperature sensor Check temperature sensor
(see page 52) (see page 52)
101