Cleaning The System; Flushing The System; Shut Off And Non-Return Valves; Start Up - Grundfos Solar 15-80 130 Installation And Operation Instruction Manual

10. Check the pressure gauge to see if the system pressure falls – eliminate any leaks where necessary.
11. Turn on the solar circulating pump, bleeding the system from the vent screw on the air-separator
(see 7. Air-separator).
12. Increase the system pressure to the operating pressure if required.
13. Regulate the system's flow as required, through adjusting the flow regulating valve (see 8. Flow
meter).
14. Set the speed of the pump to achieve the required performance curve (see 3. Technical information)
15. After several hours operating repeat points 11 and 12.
Prior to commissioning the system each connection should be checked.

10.2 Cleaning the system

Repeat point 1 to 6 in section 10.1 filling the system.

10.3 Flushing the system

Flushing the system is only required if the system has been filled only with water and there is a risk of
freezing.
Connect a re-cycle tank to a tap on the lower part of the system.
Operate on the blue monobloc ball valve the screw (see 10.4 Shut off and non-return valves) to keep
the non-return valve in the open position.
Ensure the discharge valves in the upper part of the system are open.

10.4 Shut off and non-return valves

The red and blue handles of the monobloc ball valves action the shut-off ball valves. These same
valves also have integrated non-return valves.
The blue monobloc ball valve allows the fluid to pass through in both directions through operating
the little screw on the valves body (see below). This allows the non-return valve to stay in the open
position.
For normal operation the shut-off ball valves should be completely open (handles turned fully in anti-
clockwise direction) and non-return valves should be closed.
For normal operation the shut-off ball valves should be completely open (handles turned fully
in anti-clockwise direction) and non-return valves should be closed.

11. Start up

Do not start the pump until the system has been filled with liquid and vented (see 10. Filling and
flushing the solar thermal system). The required minimum inlet pressure must be available at the
pump inlet.
Minimum inlet pressure in relation to liquid temperature
Solar 15-65 & Solar 15-80
Liquid
temperature
o
≤85 C
o
90 C
o
110 C
Warning
When pumping hot liquids, care should be taken to ensure that persons cannot accidently come
into contact with hot surfaces.
Closed non-return valve (working position)
Minimum inlet pressure
[MPa] [bar]
0.05 0.05
0.027 0.27
0.108 1.08
10