Troubleshooting; Diagnostic System - Viessmann Vitogas 100 Service Instructions Manual

Diagnostic system

System char- Cause
acteristics
The boiler will No voltage
not start
Excessive boiler
water temperature
High limit safety cut
out activated
The flue gas monitor
has responded (if in-
stalled)
Strapping plug aNS is
missing at the burner
control unit
Strapping plug aYA is
missing at the burner
control unit
Burner control No gas available (air
unit enters a in the supply line)
fault state
The pilot burner will
not light
Power supply incor-
rectly connected
Ionisation current too
low or lead broken
Control unit faults:
Measures
Check the fuse and the connections of
the power supply cable.
Check the setting of the switch on the
control unit.
Wait until the boiler water temperature
has dropped by approx. 20 K.
Press the reset button on the control
unit.
Wait approx. 17 min;
if the boiler then starts automatically,
check the flue pipe and the chimney.
If the boiler does not start automati-
cally, check the flue gas monitor (see
page 19).
Fit strapping plug aNS or a flue gas
monitoring sensor.
Fit strapping plug aYA.
Press the reset button at the burner
control unit.
Check the ignition electrode (see
page 16).
Check the gas supply.
Interchange cores "L1" and "N" of the
power supply cable.
Check the ionisation current (minimum
value 5 µA with the main burner oper-
ating) (see page 13).
Remove the pilot burner and check for
damage (see page 16).
Check the polarity of the power supply
cable.
Service instructions boiler con-
trol unit

Troubleshooting

21