Viessmann BWT 241.A Series, Installation And Service Instructions Manual

Page: 56 / 124

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3. Fill (flush) and vent secondary cir-
cuit:
■ Open air vent valve (for positions of
air vent valves, drain & fill valves,
see page 73).
■ Slightly open quick-action air vent
valve (see safety assembly on
page 30) (remains open).
■ Move the lever of 3-way diverter
valve "Heating/DHW" into its centre
position (see diagram).
4.
!
Please note
To prevent equipment dam-
age, check the flow and return
connections of the heat pump
secondary circuit for
leaks .
If there are any leaks, switch
the appliance OFF immedi-
ately, drain the water and
check the seating of the seal
rings. Replace any seal rings
that may have become dis-
lodged.
5. Check the system pressure and top
up with water if required.
Minimum system pressure: 0.8 bar
Permiss. operating pressure: 3 bar
Filling and venting the solar circuit
Danger
Overheated collector areas and
overheated heat transfer medium
can cause burns/scalding and
equipment damage.
When working on the collector
and the solar circuit with heat
transfer medium, protect the col-
lector areas against insolation.
1. Check the pre-charge pressure of the
expansion vessel.
2.
!
Please note
To prevent equipment dam-
age,
only fill the solar circuit with
Tyfocor LS.
3. Vent the solar circuit.
Minimum system pressure: 1.7 bar
Permissible operating pressure:
6 bar
Commissioning, inspection, maintenance
Further details regarding the individual steps
(cont.)
5601 598 GB