Filling And Venting The Primary Side; Filling And Venting The Secondary Side - Viessmann VITOCAL 242-G Installation And Service Instructions Manual

Commissioning, inspection, maintenance

Filling and venting the primary side

!
Please note
Commissioning when the primary circuit is
empty causes appliance damage.
Charge and vent the primary circuit before con-
necting the power supply.
1. Check the pre-charge pressure of the expansion
vessel.
2. Charge the primary circuit with Viessmann heat
transfer medium and vent.
Note
Ensure frost protection down to
Viessmann heat transfer medium is a ready-mixed
ethylene glycol-based medium. It contains inhibi-
tors for corrosion protection. The heat transfer
medium can be used at temperatures down to
19 °C.
–

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.
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.
■
■ Soften fill water with a water hardness above
3
16.8 °dH (3.0 mol/m ), e.g. with the small softening
system for heating water: See the Vitoset pricelist.
!
Please note
Escaping liquids can lead to electrical defects.
Protect electrical components of the heat pump
from escaping liquids.
1. Open any non-return valves installed on site.
2. Check the pre-charge pressure of the expansion
vessel: see page 41.
3. Fill (flush) and vent secondary circuit:
■ Slightly open quick-action air vent valve (remains
open): See safety assembly on page 20.
Move the lever of the 3-way diverter valve for
■
"central heating/DHW heating" into its centre
position: see Fig. 36.
40
3. Check the connections for possible leaks. Replace
Information on setting the primary pump
Temperature differential between primary circuit flow
and return: 3 K to 5 K
19 °C.
–
4.
5. Check the system pressure. Top up with water if
faulty or displaced gaskets.
!
Please note
Leaking hydraulic connections lead to appli-
ance damage.
■ Check the internal and on-site hydraulic
connections for leaks.
In the event of leaks, switch OFF the appli-
■
ance immediately. Drain off liquid via the
drain valve. Check the seating of seal
rings. Always replace displaced seal
rings.
required.
Minimum system pressure: 0.8 bar (80 kPa)
■
■ Permiss. operating pressure: 3 bar (0.3 MPa)