Riello KV/200 20 ISC Solar Installation And Maintenance Manual page 33

FILLING THE SOLAR HEATING CIRCUIT
Heat transfer liquid
Use only non-toxic propylene glycol as heat transfer fluid.
Mix the propylene glycol with water (preferably deminer-
alised), by pouring the glycol into a container of water
and not vice-versa. Establish the necessary concentra-
tion of glycol using the table alongside. The temperatures
given in the table define the level of anti-freeze protection
provided.
Filling procedure
- Open the non-return valve (9) to facilitate filling. See
the figure to ascertain the correct position for the dot
on the screw.
- Open the manual bleed valves on the system bleed
manifold.
- Use an external filling pump to pump heat transfer fluid
around the circuit between the cocks (A) and (B), until
all bubbles have been eliminated.
- Fill the circuit until pressure gauge (8) shows a value
of 3 bar.
- Start the solar heating circuit pump for a few minutes to
check that no air remains in the circuit.
- Adjust circuit pressure again if necessary.
- Set the non-return valve (7) to automatic functioning.
See the figure to ascertain the correct position for the
dot on the screw.
- Close the previously opened manual bleed valves on
the system bleed manifold.
- Set a flow rate proportional to the number of solar col-
lectors installed on adjuster screw (10) (2 l/min. per
collector).
b
DO NOT fill the solar heating circuit under sunny
conditions or when the collectors are hot. Risk of
burns from hot fluid inside the collectors!
b
Only open the bleed valve if the temperature of the
fluid in the circuit is below 60°C.
b
Make sure that the collectors are not hot before you
start bleeding the circuit. Always cover the solar
collectors before bleeding the circuit, and whenev-
er possible perform bleeding in the early morning.
Glycol / water proportions for different
minimum temperatures
% glycol by weight
10
20
26
30
36
40
2 60
40 80
1 3 20 100
0 120
0 4
bar °C
Minimum outdoor
temperature °C
- 3,5
- 8,0
- 12,5
- 15,0
- 20,0
- 24,0
AUTOMATIC
8
OPEN
9
A
10
11
B
INSTALLER
33