26
6.3 F
LUSHING THE
S
YSTEM USING
W
ATER
To remove any contaminants, the solar system has to be flushed with heat
transfer fluid or water prior to final filling, for glycol flushing and filling see
6:2.
Flushing and filling with water can be done using a conventional filling loop
from the mains supply. The mains pressure must be capable of pressurising
the system to 3.5 bar.
If 3.5 Bar is not achievable from a filling loop a suitable electric pump or
hand pump which should be used.
Flushing Procedure using water - refer fig. 6.3A
1.
Carry out the pre-fill check - see 6.1.
2.
Remove pump group cover.
3.
Connect one end of the water flow pipe to fill connection A, the other
end is either connected to a mains filling point, or to a pump
arrangement.
4.
Connect return flushing pipe to connection B, the other end either
goes to a drain or suitable collector.
5.
Open valves C then D.
6.
Open non-return valve shut off E.
7.
Check the flow shut off valve with integral temperature guage F is
open, the red housing should be vertical (90°CW) as shown.
8.
Check the return shut off valve with integral temperature guage G is
open, the blue housing should be vertical (90°CW) as shown.
9.
Set Flow Rate to maximum H (slot vertical) - see 5.16.
10. Close air bleed valve J.
11. Open the air vent(s) at the system high point(s).
12. Open filling loop or start pumping water through the system. As the
pumped water will take the route of less resistance it will flow through
the pump and then return to the drain or container.
13. After a short period close the ball valve G by turning the blue
thermometer housing (CCW). This will divert the flow in the normal
direction of the system.
14. When flushing is complete close valve C (flush return). The system
will now start to fill. Fill the system slowly to encourage air to escape.
15. Raise the system pressure to 3.5 Bar to improve air removal and to
check all connections are sound.
16. Stop pump or shut off filling loop (as applicable).
17. Check air bleed valve J for air.
18. Check system for leaks.
19. Return system pressure to the required ‘system fill pressure’ as shown
on chart 6.5.
20. Shut off valve D, then disconnect filling pipe.
21. Allow as much water as possible to drain from the system through
valve C, then shut off valve C and disconnect drain pipe.
22. Drain ALL the remaining water out of the system by opening the
system drain point/s at the lowest part of the system.
23. When ALL water has been drained close drain points.
24. Fill system with glycol - see 6.4.
IMPORTANT
The indirect cylinder MUST be fully
filled before filling the solar circuit.
Failure to do so may result in
irreparable damage to the cylinder.
IMPORTANT
After the system has been flushed
with water it must be completely
drained of water before filling with
glycol to ensure the glycol fill is of
the correct concentration.
