Checking The Expansion Vessel And Heating Circuit Pressure - Viessmann Vitocal 200-G Series Installation And Service Instructions Manual

Commissioning, inspection, maintenance
Filling and venting the secondary side
Unsuitable fill and top-up water increases the level of
deposits and corrosion. This can lead to system dam-
age.
Hard water can also cause damage to the instantane-
ous heating water heater in particular.
Observe VDI 2035 regarding quality and amount of
heating water, including fill and top-up water.
Flush the heating system thoroughly before filling.
■
■ Only fill with water of potable quality.
■ Only fill and operate appliances that have an instan-
taneous heating water heater with softened water.
A
Fig. 45
3-way diverter valve "central heating/DHW heat-
A
ing"
Air vent valve, secondary circuit
B
Drain & fill valve, secondary circuit
C

Checking the expansion vessel and heating circuit pressure

Observe engineering information.
Brine/water heat pump technical guide
54
B
4.
C
1. Open any non-return valves installed on site.
2. Check the pre-charge pressure of the expansion
vessel.
3. To fill (flush) and vent the secondary circuit, open
the secondary circuit air vent valve.
4. To vent the secondary circuit to the DHW cylinder,
move the lever of 3-way diverter valve "central
heating/DHW heating" into its centre position.
5. Check the system pressure. Top up with water if
required.
Minimum system pressure: 0.8 bar (80 kPa)
Permiss. operating pressure: 3 bar (0.3 MPa)
!
Please note
To prevent equipment damage, check the flow
and return connections of the heat pump secon-
dary circuit for leaks.
In the event of leaks, switch off the appliance
immediately. Drain off the water. Check the seat-
ing of seal rings. Replace any seal rings that
may have become dislodged.