Checking The Expansion Vessel And The System Pressure; Checking The Electrical Connections; Starting The Heating System - Viessmann Vitosol 200-T Service Instructions For Contractors

Further details regarding the individual steps

Checking the expansion vessel and the system pressure

1. Drain the system. For this, close the
cap valve on the expansion vessel (if
installed) and reduce the pressure.
2. If the pre-charge pressure of the
expansion vessel is lower than the
set value, top up with nitrogen until
the pre-charge pressure equals the
set value.
Static head (top edge of collector to
expansion vessel): ........... m
Set pre-charge pressure of the
expansion vessel:
0.7 bar + 0.1 x static head in m
0.7 bar + 0.1 x ......... m = ........ bar

Checking the electrical connections

Check the tightness of the electrical
plug-in connectors and cable grommets;
check cables for damage.

Starting the heating system

Observe operating instructions of instal-
led components.
Commissioning, inspection, maintenance
3. Top-up heat transfer medium until the
system pressure is 0.3 to 0.5 bar
higher than the set pre-charge pres-
sure of the expansion vessel (create
a safety water seal in the expansion
vessel).
The safety water seal should be
0.005 x liquid content of the complete
system, but no less than 3 litres.
Liquid content of the system = con-
tent of pipes + content of collectors +
content of the indirect coil of the DHW
cylinder and safety water seal for the
expansion vessel.
(cont.)
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