What Needs Doing; System Characteristics - Viessmann Vitodens 100 Installation And Service Instructions Manual

What needs doing?

System characteristics

What to do if ...
... the heating system
doesn't come on
... the boiler does not
switch on (or switches on
infrequently)
... the burner doesn't
ignite, the fault symbol
"U" is displayed and
"Reset" flashes red
... the burner doesn't
ignite, display shows
fault symbol "U"
... the burner switches off
although the desired
room temperature hasn't
been reached
12
Cause
System switch switched
off
System controls includ-
ing room thermostats
not calling for heat.
Knob "tr" is set to "9" Set required heating
Fuse has triggered
(either at the fuse board
or in the controls)
No gas
Control fault
False start
Control fault
Fault in air supply or in
the flue
Heating water tempera-
ture or room tempera-
ture is set too low
Solution
Switch on
Switch on System con-
trols to create demand.
water temperature (see
page 9)
Contact your heating en-
gineer
Contact your gas utility
supplier or heating engi-
neer
Read off the fault codes
in the display. Contact
your heating engineer
and report fault codes.
Press "Reset" button. If
this attempt to start is
also unsuccessful con-
tact your heating engi-
neer.
Read off the fault codes
in the display. Contact
the heating engineer and
report fault codes.
Contact your heating en-
gineer.
Increase heating water
temperature by turning
knob "tr" (see page 9)
or increase desired room
temperature (see room
thermostat control man-
ual).