Viessmann VITOMAX 200-HS Operating And Service Instructions page 14

Operating information
Functions
(cont.)
Air vent shut-off valve wQ
Function
Venting the boiler
during filling or
after a new sys-
tem start from
atmospheric
pressure
Steam shut-off valve wW
Function
Main boiler shut-
off towards the
steam mains
Blow-down wT and wZ
Function
■ Periodic removal of sludge deposits
Method of operation
Automatic blow-down via programma-
ble valve at regular intervals
Manual blow-down at regular intervals
or in accordance with country-specific
regulations
!
Please note
When acting manually, be mind-
ful of the lever kickback
14
Operation
During heat-up,
open the valve and
close it again, as
soon as visible
steam is expelled
Operation
Enable steam or
close boiler with
damper valves
Operating information
Air / steam must be able to be routed away
safely
Operating information
Open slowly to prevent water hammer
Operating information
The programmable switch opens via the
control valve of the blow-down valve and
briefly drains off boiler water. The vacuum
force thus created removes the sludge from
the boiler
Manual activation possible at any time
Push the locking lever of the blow-down
valve to the side
Push down on the activating lever of the
blow-down valve for two to three seconds
Please note
When acting manually, be mindful of the
lever kickback