Heatrae Sadia ELECTROMAX SOLAR Installation & Servicing Instructions Manual page 40

4.7.1 SET EXPANSION VESSEL CHARGE PRESSURE
1. The solar expansion vessel charge pressure should be set before the solar primary circuit
is flushed and filled.
2. Calculate the system pressure: The system pressure should be 0.07 MPa (0.7bar) above
the static pressure (static pressure = 0.01 MPa (0.1bar) x static height where the static
height = the distance in metres between the top of the Electromax Solar and the highest
point of the solar primary circuit, usually the top of the collectors), however it must be at
least 0.15 MPa (1.5bar) and no more than 0.22 MPa (2.2bar).
3. Set the solar expansion vessel charge pressure to 0.05 MPa (0.5bar) below the system
pressure. Pressure is checked using a car tyre pressure gauge. The valve is located at
the opposite end of the solar fluid connection.
4.7.2 FLUSHING THE SOLAR PRIMARY PIPEWORK
1. Before the system is commissioned the pipework must be flushed to remove any con-
taminates. This must be done using the solar heat transfer fluid as it will be impossible to
fully drain all parts of the system.
2. Ensure power is switched off.
3. Connect a filling hose to the top fill point on the solar flow meter and the filling pump.
4. Connect a drain hose to the bottom drain point on the solar flow meter. The drain hose
should convey flushed heat transfer fluid to a suitable container.
5. Open the fill and drain valve on the flow meter (the handles should be turned so they are
horizontal)
6. Open both solar check valves (the handles should be turned so they are vertical).
7. Close the flow meter adjustment screw (turn the slot so that it is horizontal).
8. Pump the heat transfer fluid into the solar circuit until it starts to come out
hose.
9. Continue to pump heat transfer fluid through the solar system until all the pipework and
components have been thoroughly flushed. NOTE: Flushed fluid may be re used if it has
been filtered.
10. When satisfied that all pipework and components have been flushed the system can be
filled
4.7.3 FILLING THE SOLAR PRIMARY PIPEWORK
1. Ensure power is switched off and fill and drain hoses are connected as described on sec-
tion 4.7.2 steps 3 and 4 above.
2. Pour an amount of solar heat transfer fluid into the filing pump.
3. Close the fill valves on the flow meter (the handles should be turned so they are vertical)
and pressurise the pump slightly prior to filling the system. If an electric pump is being
used follow the instructions with the pump.
4. Open the fill valve on the flow meter (the handle should be turned so it is horizontal) and
pump fluid into the system. Whilst pumping, open the flow meter drain valve slightly to
allow air to vent out of the system.
5. When the pump is down to approximately 1 litre isolate the fill and drain valves. Vent the
pump and re fill with solar heat transfer fluid.
6. Re-pressurise the filing pump and repeat steps 6 & 7 until fluid is seen discharging from
the flow meter drain valve. Close the drain valve.
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of the drain