Viessmann VITOPEND 200 Installation And Service Instructions Manual page 30

Initial start-up, inspection, maintenance
Further details regarding the individual steps
A Close the boiler fill & drain valve
30
(cont.)
1. Switch ON the control unit and call
up the relay test:
Constant temperature control
unit:
K + d press simultaneously for
at least 2 s
a/b
press, until "5" is dis-
played.
Weather–compensated control
unit:
K + d press simultaneously for
at least 2 s
a/b
press, until "Valve centre
pos." is displayed.
2. Wait until the valve has moved into
its centre position (approx. 5 s),
then switch OFF the main ON/OFF
switch "8" at the control unit.
3. Drain the heating system via the
boiler fill & drain valve A.