Viessmann VITOLIG 300 Service Instructions Manual page 24

Troubleshooting
Fault messages
(cont.)
Display Explanation/Cause/Effect
indication
AL 037 The pellet supply flap does not
close after the supply is com-
pleted.
No pellets reach the hopper.
The pellet supply vacuum tur-
bine does not switch off.
The boiler will not start.
AL 062 Air damper faulty (if installed).
AL 071 The heating system emergency
stop switch is switched off.
The boiler completely burns the
available fuel.
AL 076 Boiler water temperature sen-
sor faulty.
The boiler completely burns the
available fuel.
AL 078 Combustion chamber tempera-
ture sensor faulty.
The boiler completely burns the
available fuel.
AL 085 Safety sensor at the supply
auger faulty.
The boiler completely burns the
available fuel.
AL 128 Supply auger blocked by a for-
eign body. The flame goes out
during operation.
The boiler completely burns the
available fuel.
24
Remedy
Open the pellet hopper, clean
the flap and return into an opera-
tion state (see page 16).
Finally, press reset on the con-
trol unit.
Replace the control unit.
Check the air damper, then
press reset.
Switch ON the heating system
emergency stop switch.
Check the boiler water tempera-
ture sensor (see page 26).
Replace the combustion cham-
ber temperature sensor.
Replace the safety sensor.
Clean the hopper (see page 16)
and remove the foreign body
through the opening above the
supply auger.
Refill the hopper.
Clean the combustion chamber,
burner pot and secondary heat-
ing surface (see page 12 and
13).
Check the flue pipe and clean, if
required.
During commissioning, the mes-
sage "AL 171" can be shown
several times. In such cases, al-
ways press the reset button.