Checking Electrical Connections Of The Internal Unit For Firm Seating; 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
Replacing the magnesium anode
!
Please note
A short circuit between the magnesium anode
and the internal indirect coil negates the protec-
tive effect of the magnesium anode. This leads
to corrosion damage on the DHW cylinder.
Before connecting the electrical cables, check
the resistance across terminals
Fig. in chapter "Cleaning the DHW cylinder"). If
the resistance is significantly less than infinity,
check whether the magnesium anode is touch-
ing the internal indirect coil.

Checking electrical connections of the internal unit for firm seating

Checking the free running of the fan in the external unit

Danger
Contact with the fans while they are operating
can result in serious cutting injuries.
Isolate the external unit from the power supply
■
and safeguard against reconnection.
■ Do not open the appliance until the fan has
come to a stop.

Cleaning the external unit heat exchanger (evaporator)

Danger
Touching 'live' components and their contact
with water can result in serious injury due to
electric shock.
Isolate the external unit from the power supply
■
and safeguard against reconnection.
Protect the external unit against moisture.
■
Danger
Contact with the fans while they are operating
can result in serious cutting injuries.
Isolate the external unit from the power supply
■
and safeguard against reconnection.
■ Do not open the appliance until the fan has
come to a stop.
Cleaning with compressed air
1. Open the external unit casing.
Danger
The sharp edges of the heat exchanger
(evaporator) can cause injuries.
Avoid contact.
56
(cont.)
and (see
A B
1. ■ Type AWT/AWT-AC 221.A04:
First remove the top cover and then the front
panel.
Type AWT/AWT-AC 221.A05 to A13, 221.B10 to
■
B16:
Remove the external unit air discharge grille.
2. Turn the fan by hand.
!
2.
Clean the heat exchanger from the inside out with
compressed air.
3. Check the aluminium fins of the heat exchanger for
deformation and scratches. If necessary, repair with
a suitable tool (e.g. fin comb).
4. Close the external unit casing.
Please note
Excessive air pressure from the front and
sides can result in the deformation of the alu-
minium fins of the heat exchanger.
Only point the compressed air gun at the
heat exchanger from the front and from an
adequate distance.