Filling The Heat Transfer Medium; Pressure Test; Commissioning - Stiebel Eltron SOL 23 PLUS Utilisation Et Installation

2.11 Filling the heat transfer
medium circuit
Observe the EC safety datasheet for
!
H-30 L, and fit a copy somewhere
accessible at the system. Wear protective
gloves and goggles when handling H-30 L or
H-30 LS.
Never fill the system when it is subject to
strong insolation. This could lead to steam
hammer inside the collectors.
If the sun shines during commissioning, cover
the collectors or wait until there is some shade.
Never fill and pressure test the system with
water when there is a risk of frost.
Fill the system after the pipework installation,
after connecting the collectors and filling the
cylinder.
Use a solar filling facility for filling the system.
Alternative: Comparable power drill
AF
available from DIY stores.
Flushing the system
Preparations:
Set the pressure vessel prior to filling the
system to an pre-charge pressure of 3.0 bar
During all filling and draining procedures,
open the air vent valve at the highest point of
the system. Close the air vent valve again as
soon as liquid is expelled.
Potable water without heat transfer medium
is generally used for the initial fill for pressure
testing.
Never fill the system with water when
!
there is a risk of frost.
Close the flow meter adjusting screw at the
pump assembly (horizontal position). Connect
a garden hose at the upper open fill & drain
valve and let water run through the collectors
to the lower open fill & drain valve.
Fill the system slowly and continue this
process, until clear water is expelled from the
open drain valve.
Drain the water off after flushing has been
completed.
Filling and venting the system
Fill the solar heating system exclusively with
H-30 L or H-30 LS heat transfer medium. The
bottles have been premixed and require no
further treatment.
Never admix water or alternative
!
process media; otherwise the essential
characteristics and corrosion protection can no
longer be guaranteed.
For that reason, the system may also not be
topped up with water.
38
Connect the hose to the filling pump:
AF
- From the pump (pressure side) to the top
fill & drain valve
- From the bottom fill & drain valve into the
heat transfer medium container
- From the heat transfer medium container to
the pump (inlet side)
- Start the fill pump and pump the heat
transfer medium into the system
Flush the system until no more bubbles are
expelled from the drain hose.
For an easy removal of any air pockets or
buffers from the system, open the bottom fill
& drain valve during the flushing process and
let the fill pump build to a system pressure of
approx. 2 to 3 bar.
Then fully open the bottom fill & drain valve.
During this process, firmly hold the drain hose
inside the container.
Repeat this process approx. 3 to 5 times.
Close the bottom fill & drain valve after
completing this ventilation step and raise the
system pressure to 3.5 bar.
Then also close the top fill & drain valve.
Now open the air vent valve at the highest
point, until only heat transfer medium is
expelled.
Raise the system pressure in a cold state to its
operating pressure of 3.5 bar.
Let the solar heating system rest over night and
vent again in the morning via the air vent valve
before solar radiation affects the collectors.
Close the air vent valve again.
Close both fill & drain valves with the caps
supplied.
If the system does not start automatically,
there may still be air in the system. Repeat the
venting process, if required.
AF
Hose
Power drill
pump
Power drill
Heat transfer
medium
The safety valve drain must terminate
!
in a container that complies with
DIN 4757 [or local regulations], and that can
hold the entire system contents.
For this, the empty heat transfer medium
container is sufficient in smaller systems.
Dispose of spent heat transfer medium
H -30 L by permissible means.

2.12 Pressure test

After the pipework has been installed and the
collectors have been connected, carry out a
pressure test of the system.
Carry out the pressure test exclusively
!
with H -30 L or H -30 LS heat transfer
medium.
The test pressure is 7.8 bar (1.3 x the
permissible operating pressure to DIN 4757).
The pump is connected to the filling connector
of the SOKI. For this, remove the safety valve
and seal the connection.
Refit the safety valve correctly after
!
the pressure test has been completed.
Only fit the thermal insulation after the leak
test has been successfully completed.
Tightness test.
Close the bottom fill & drain valve and raise the
system pressure up to 6 bar and let the system
stand a few hours. Check all fittings. Drain the
system fully.
In case there is a risk of frost, immediately fill
the system with heat transfer medium.

2.13 Commissioning

Retighten all fittings prior to commissioning.
The minimum filling pressure of a
!
cold system (below 30 °C) is 3.5 bar.
Complete the "commissioning report" after
commissioning.
Set the integral control unit to manual to
check, whether all required relays of the solar
control unit are connected. For this, observe
the operating instructions of the respective
control unit.
Then set the control unit back to automatic
mode.
The system should then start automatically
subject to all starting conditions being met. If
this is not the case, check in chapter "What to
do if ..." for a possible cause for this fault.