Replacing The Magnesium Anode; Checking That Condensate Can Drain Away Freely From The External Unit Condensate Pan 14. Checking The Free Running Of The Fan In The External Unit; Cleaning The External Unit Heat Exchanger (Evaporator) - Viessmann VITOCAL 222-S Installation And Service Instructions Manual

Commissioning, inspection, maintenance
Further details regarding the individual steps

Replacing the magnesium anode

Note
If the magnesium anode needs to be
replaced, a maintenance-free impressed
current anode (accessory) can be used.
For removal of the magnesium anode,
see chapter "Cleaning the DHW cylin-
der".
Checking the free running of the fan in the external unit
Danger
Starting the fan with the external
unit open can lead to severe inju-
ries.
Isolate the external unit from the
power supply and safeguard
against reconnection.
Be aware that the fan may run
on.

Cleaning the external unit heat exchanger (evaporator)

Danger
Touching 'live' components and
their contact with water can result
in severe injury due to electric
shock.
Isolate the external unit from the
power supply and safeguard
against reconnection.
Be aware that the fan may run
on.
74
!
Please note
A short circuit between the mag-
nesium anode and internal indi-
rect coil increases the protective
effect of the magnesium anode
and leads to corrosion damage
on the DHW cylinder.
Before inserting the electrical
cables, measure the resistance
between terminals A and B
(see previous diagram). If the
resistance is significantly less
than infinity, check whether the
magnesium anode is touching
the internal indirect coil.
1. ■ Type AWT-AC 221.A04:
First remove the top cover and then
the front panel.
■ Type AWT-AC 221.A07 to A13,
B10, B13:
Remove the external unit air dis-
charge grille.
2. Turn the fan by hand.
Cleaning with compressed air
1. Open the casing of the external unit.
!
Please note
The sharp edges of the heat
exchanger can cause inju-
ries.
Avoid contact with the heat
exchanger.
(cont.)