DRAINING THE BOILER
Essential recommendations for safety
•
Before draining the DHW tank, drain the heating (primary) circuit or bring its
pressure to 0 bar.
•
Water flowing out of the drain valve may be extremely hot and could cause severe
scalding. Keep people away from the hot water discharge.
Set-up conditions
•
Boiler switched off using the ON/OFF
master switch
•
External power supply isolated
•
Fuel/gas supply closed
Heating circuit draining procedure
1.
Close the isolating valves (
1
).
2.
Connect the drain valve (
2
) to the sewer
with a hose.
3.
Open the drain valve (
2
) to empty the
heating circuit of the boiler.
4.
Close the drain valve (
2
) once the heating
circuit of the boiler is empty.
DHW circuit draining procedure
Before draining the DHW tank,
make sure that the heating
(primary) circuit pressure is null.
1.
Open fully a draw-off tap (
3
) for
about 60 minutes to make sure that
the DHW tank has cooled down.
2.
Close the isolating valves (
1
).
3.
Connect the drain valve (
2
) to the
sewer with a hose.
4.
Open the drain valve (
2
) and drain
the DHW tank water to the sewer.
5.
Open the draw-off tap (
3
) to
accelerate the draining process.
If it is located lower than the tank
connection, open a draw-off tap
located higher in the system.
6.
Close the drain valve (
2
) and the
draw-off tap (
3
) once the DHW
tank of the boiler is empty.
Cold water
Hot water
1
1
2
1
2
3
1
2
3
HeatMaster 25 C: A1003474 - 664Y7000 • B
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39
MAINTENANCE
REMOVAL, CHECK AND INSTALLATION OF THE BURNER ELECTRODE
Set-up conditions
•
Boiler shut down
•
External power supply isolated
•
Gas supply closed
•
Front and top panels removed, refer to “Removal and Installation of the Front and Top Panels” on
page 32.
Removal procedure
1.
Disconnect the electrode grounding cable from the electrode.
2.
Disconnect the electrode ignition cable from the electrical box.
3.
Remove two mounting screws (
1
) and retain them for reinstallation.
4.
Remove the electrode (
2
) and the gasket (
3
).
5.
Check the correct alignment of the electrode ends and that the gap corresponds to the values
indicated on the figure below.
6.
If the electrode is in bad condition, replace it.
Installation procedure
1.
Install a new gasket (
3
).
2.
Install the electrode (
2
) using the two screws (
1
), torque i.a.w. “Torque Values” on page 41.
Follow-on tasks
1.
Reconnect the grounding cable to the electrode.
2.
Reconnect the ignition cable to the electrical box.
Essential recommendation for the correct operation of the appliance
•
Remove the electrode to control it in case of ignition problems.
Min. 3 mm
Max. 4 mm
