Viessmann Vitocal 252-A Series - Replacing the Protective Magnesium Anode; Draining the Appliance on the DHW Side

114
ABC
Fig. 78
1.
Remove thermal insulation
C
.
2.
Remove earth cable
B
from protective magne-
sium anode
A
.
3. Connect the tester (measuring range up to 5 mA)
in series across tab
A
of protective magnesium
anode and earth cable
B
.
Anode earth
current
Protective magnesium anode
> 0.3 mA Function OK
< 0.3 mA Visual inspection required: See
chapter "Testing the protective
magnesium anode".
4.
Insert thermal insulation
C
.
Checking the protective magnesium anode
We recommend replacing the protective magnesium
anode once it has been reduced to a diameter of 10 to
15 mm.
Replacing the protective magnesium anode
Note
If the protective magnesium anode needs to be
replaced, a maintenance-free impressed current anode
(accessories) can be used.
For removal of the protective magnesium anode: See
diagram in chapter "Cleaning the DHW cylinder".
Draining the appliance on the DHW side
1. Shut off the drinking water supply.
Ensure adequate ventilation in the DHW pipework
by opening a cold and hot water tap.
Danger
The uncontrolled escape of DHW can cause
scalding and building damage.
Only open DHW and heating water connec-
tions with a depressurised DHW cylinder.
Commissioning, inspection, maintenance
Checking the anode earth current with an anode tester
6222080