Viessmann Vitocrossal 200 Service Instructions For Contractors page 39

Air pressure switch
Combustion chamber pressure monitoring function (LDW2)
B
To monitor the combustion chamber
pressure, the switching threshold of air
pressure switch 2 (LDW2) is monitored
in all operating phases (except during
safety and stabilising time).
Air pressure switch C triggers a fault
shutdown at the burner control unit under
the following circumstances:
■ If the combustion chamber pressure is
outside the permissible range in the
pre-purge phase, in control mode or in
the post-purge phase after 2 attempts.
The fault shutdown is shown with fault
indicator "F FB" on the burner control unit
display (see page 40) and can be reset
by pressing reset button B.
(cont.)
C
Rated Rated
heating heat in-
output put
P Q (H
max max
(50/30 °C)
in kW in kW
400
500
620
Air pressure switch
Setting value
LDW2
)
i
in mbar
381
474 5 ↑
593
39