10
Hot Water Storage Tank with Coil
WTB 220-400
Chapter 5 |
Chapter 6 |
Maintenance
Accessories and Spare Parts
6 Accessories and
spare parts
Fig. 11
Installation of the inspection opening cover
(mounting order).
Cleaning of the Storage Tank
During the use of the tank, the so-called boiler scale
precipitation occurs from the heated water. The amount
of deposited stone depends on the hardness of water,
working temperature and time of use. Covering the
heating surfaces with stone reduces their heating effi -
ciency, increases energy consumption and lengthens
the heating time. It is recommended to clean the tank
from accumulated deposits at a frequency of at least
once a year. In the case of hard or very hard water, it is
necessary to carry out cleaning more frequently.
Accessories and spare parts for WTB storage tanks
can be purchased at our distributors or authorized
service centres.
Once cleaned, the unit is ready to use.
Storage tank cleaning procedure:
1. Prepare a new inspection opening gasket. The
old gasket may not be reused (for the list of the
inspection opening gaskets, see Section “Acces-
sories and Spare Parts”).
2. In storage tanks with the electric heating unit in-
stalled, disconnect power from the unit fi rst.
3. Switch the storage tank coil heaters OFF and
wait until the water inside cools down.
4.
Cut-off the hot water supply and drain the storage
tank through the drain valve (see Fig. 7 item QM1)
5. Remove the inspection opening blanking plate
and gasket
6.
Remove the inspection opening screws and fl anged
cover and fl ush the storage tank and remove ac-
cumulated sludge and lime slurry. If necessary, re-
move lime deposits from the coil – this guarantees a
proper heat exchange. Pay special attention to not
damage the ceramic enamel coating.
7. Replace a new gasket and the inspection opening
fl anged cover. Screw tightening torque according
to the Table 1
8. Fill the tank with water and vent it as described in
par. Start-Up.
9. Check tightness of the inspection opening.
10. Replace the insulation and inspection opening
blanking plate.
Storage tank
model
Inspection
opening dia. Type of gasket
WTB
220-400
ø 120
Flanged gasket
ø 150
Fig. 12
Mounting kit for electric heating module –
– fl anged cover with 1 ½” sleeve.
Table 3.
Mounting kit for electric heating module
Table 2.
Inspection opening gaskets
Torque
(Table 1)
Storage tank
model
Inspection
opening dia-
meter
Tightening
torque
WTB
220-400
ø 120
25 ± 5 Nm
Table 1.
Tightening torque
Type
Application
Mounting kit for electric heating
module -
1½” female
WTB 220-400
NOTE
During mechanical cleaning, be careful to
not damage the enamel. In the case of che-
mical cleaning, pay special attention to neu-
tralize the chemicals used for cleaning.