Completion; Fill And Vent The System - Grant Combi 70 V3 User's Installation Manual

7.1 Fill the system
1 Automatic air vent(s) are fitted to the top of the
boiler. Check that the small cap on the top of each
air vent is screwed on fully, then unscrew it one
complete turn - the cap remains in this position
from now on.
2 If the flexible filling loop is used to fill the system, ensure
it is connected and that the valve connecting it to the
boiler is open and the valve at the front is closed.
A valve is open when the operating lever is in line with
the valve, and closed when it is at right angles to it.
3 Ensure that the mains cold water supply valve is open
(operating lever in line with the valve), then turn on the
mains cold water supply and gradually open the front
valve on the filling loop until water is heard to flow.
4 Vent each radiator in turn, starting with the lowest
one in the system, to remove air.
5 It is important the circulating pumps are properly
vented to avoid them running dry and the bearings
being damaged.
To gain access to the pump in the Combi V3 and
Combi Max, and the Heating pump in the Vortex
Combi, it is necessary to lower the control panel.
Loosen (but do not remove) the four fixing screws
securing the control panel to the side panels, hinge
the panel forward to gain access to the pump.
Unscrew and remove the plug from the centre of
the pump. Using a suitable screwdriver rotate the
exposed spindle about one turn. When water starts
to trickle out, replace the plug.
On the Vortex Combi the Hot water pump must
also be vented as described above.
6 Check the operation of the safety valve by turning
the head anticlockwise until it clicks. The click is
the safety valve head lifting off its seat allowing
water to escape from the system.
Check that this is actually happening.
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7 - FILL AND VENT THE SYSTEM

Combi V3, Combi Max and Vortex Combi models
7 Continue to fill the system until the pressure gauge
indicates between 0.5 and 1.0 bar. Close the fill
point valve and check the system for water
soundness, rectifying where necessary. Water may
be released from the system by manually operating
the safety valve until the system design pressure is
obtained.
8 The system design pressure (cold) should be
between 0.5 bar and 1.0 bar. The pressure is
equivalent to the maximum static head in bar + 0.3
(1 bar = 10.2 metres of water), where the static
head is the vertical height from the centre of the
expansion vessel to the highest point of the system.
9 Close the valves either side of the filling loop and
disconnect the loop.
7.2

Completion

Please ensure that the OFTEC CD/10 installation
completion report (provided with the boiler) is
completed in full.
Leave the top copy with the User. Retain the two
carbon copies.
Ensure that the User Information pack (supplied with
the boiler) is handed over to the Householder.