9
Hot Water Storage Tank with Coil
WTB 220-400
Chapter 5 |
Maintenance
In order to check the degree of wear of the anode, do
the following (see Fig. 9):
1. Remove the housing cover together with thermal
insulation.
2. Disconnect the connecting conductor (protective)
from the storage tank top head.
3. Connect an electric meter (range in mA) between
the protective conductor and the M5 threaded pin
and measure the intensity of the protective direct
current.
When replacing the magnesium anode, follow the
procedure below (see Fig. 10):
1. In units with the electric heating unit installed, dis-
connect power from the unit fi rst.
2. Switch the storage tank coil heaters OFF and
wait until the water inside cools down.
3.
Cut-off the hot water supply and drain some wa-
ter from the tank through the drain valve (see Fig.
7 item QM1).
4. Remove the housing cover together with thermal
insulation (1).
5. Remove the anode protective conductor (2).
6. Remove the worn magnesium anode (3).
7. Screw the new magnesium anode.
8. Connect the anode protective conductor to the
storage tank.
9. Fill the tank with water and vent it as described in
par. Start-Up.
10. Check tightness of the installed anode.
11. Reinstall the thermal insulation and the housing
cover.
Intensity of the protective direct current should not be
lower than 0.3 mA at full storage tank. If it is too low,
remove the anode and check its wear visually. If the
anode is signifi cantly corroded (above 50 % loss),
replace it immediately. Connect the anode protective
conductor to the tank after the measurement.
Once making the above steps, the storage tank is
ready to use.
Ensure that the anode protective conductor is con-
nected to the storage tank top head after installing the
new isolated magnesium anode. Lack of connection
of the anode with the tank will completely block the
work of the anode and the tank will be deprived of
corrosion protection.
Replace the protective magnesium anode every 24
months (regardless the measurement). In replace-
ment of the magnesium anode, you can use a tita-
nium anode, which you do not need to replace. Its
assembly should be carried out in accordance with
the assembly manuals of the anode manufacturer.
Measurement of the Protective
Magnesium Anode Wear
Replacement of the Protective
Magnesium Anode
Fig. 9
Measurement of the protective direct current
intensity.
Fig. 10
Replacement of the protective magnesium
anode.
1
2
3
Connect the anode protective conductor to the M5 pin
fi xed to the top head of the storage tank.
PE
M5 pin
0,3 mA
Caution
If the current intensity measurements do not
indicate any wear of the anode, its max ope-
rating time is not longer than 24 months. The
anode should be replaced after this time.
Caution
The replacement of the magnesium protecti-
ve anode should be carried out at least once
every 24 months during the warranty period.
After the warranty expires, the frequency of
replacing the protective anode depends on
the degree of wear .Timely replacement and
correct installation are a condition for mainta-
ining the tank warranty.