Viessmann Vitodens 222-F Installation And Service Instructions For Contractors page 91

Fault codes
(cont.)
Fault code dis- System characteristics
played
4D Mixer being closed
50 No DHW heating
51 No DHW heating
58 No DHW heating
59 No DHW heating
70 Burner blocked
71 Burner blocked
73 Burner blocked
74 Burner blocked or in a fault
state
75 Burner blocked or in a fault
state
76 Burner blocked or in a fault
state
80 Burner in a fault state
Cause
Incorrect assignment of
extension for mixer, heat-
ing circuit 3
Short circuit, cylinder tem-
perature sensor
Short circuit, outlet tem-
perature sensor
Lead break, cylinder tem-
perature sensor
Lead break, outlet temper-
ature sensor
Gas pressure switch pre-
vents burner start.
Mains voltage too low
Feedback input from inter-
nal H1 extension prevents
burner start.
Temperature limiter earth
fault
Internal H1/H2 extension
earth fault
Gas pressure switch earth
connection
Insufficient gas supply
Troubleshooting
Measures
Check and adjust rotary selector
S1 (see page 109)
Check sensors (see page 104)
Check sensor (see page 104)
Check sensors (see page 104)
Check sensor (see page 104)
Check gas supply (gas pres-
■
sure).
If installed: check gas pressure
■
switch for correct function.
If necessary, disconnect plug 111
from the control unit and check
whether the burner starts.
Check the power supply.
Check that internal H1 extension
and any devices connected to it
are correctly connected and work-
ing properly (internal: plug 53/96
power interruption)
Check temperature limiter, con-
necting cables and plug-in connec-
tion for connection (contact) to
earthed components. Remove con-
tact if necessary.
Press reset button R.
Check internal H1/H2 extension,
connecting cables and plug-in con-
nection for connection (contact) to
earthed components. Remove con-
tact if necessary.
Press reset button R.
Check gas pressure switch, con-
necting cables and plug-in connec-
tion for connection (contact) to
earthed components. Remove con-
tact if necessary.
Press reset button R.
Test static gas pressure and gas
flow pressure.
Check that on-site gas line and gas
flow switch are correctly sized.
Note
If the building pressure regulator
has a leak, you may notice rising
pressure when the burner is idle.
The gas flow switch may respond if
the system is restarted.
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