Descaling The Electric Emergency/Booster Heater; Protective Anode; Valves; Condensate Drain - STIEBEL ELTRON WWK 221 electronic Bedienung Und Installation

INsTALLATIoN
Maintenance and cleaning
15.5 Descaling the electric emergency/booster
heater
Only descale the electric emergency/booster heater after disas-
sembly. Never treat the inside of the DHW cylinder or the im-
pressed current anode with descaling agents. The electric emer-
gency/booster heater is inserted centrally from above into the
DHW cylinder of appliance.
1
1 Electric emergency/booster heater with protective anode

15.6 Protective anode

The flange of the electric emergency/booster heater is equipped
with a protective anode that protects the appliance from corrosion
while it is connected to the power supply. The protective anode is
a maintenance-free impressed current anode.
If a fault code in the display indicates that the protective anode is
faulty, proceed as follows:
f Remove the controller of the electric emergency/booster f
heater.
f Check the protective anode and its wiring. f
f Refit the controller of the electric emergency/booster heater. f

15.7 Valves

Regularly check the valves in the system (safety valve, pressure
reducing valve, drain valve) to ensure the operational reliability
of the appliance. The amount of limescale deposits depends on
the local water quality.
f Check all valves in the system and remove limescale deposits. f
f Replace the valves if necessary. f
f Check the function of the valves. f

15.8 Condensate drain

f Check whether the condensate drain is clear of obstructions. f
Remove any dirt.
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15.9 Replacing the power cable

WARNING Electrocution
The power cable must only be replaced (for example
if damaged) with an original spare part by a qualified
contractor authorised by the manufacturer (connection
type X).

15.10 Fitting the casing ring

WARNING Electrocution
f Reconnect the earth cable to the casing ring. f
f Fit the upper casing ring. The casing ring overlaps along the f
joint. A tab on one end clips into the recess at the other end
of the casing ring.
f Secure the casing ring with screws. f
f Fit the pipe collar of the condensate drain and the conden- f
sate drain bend.

15.11 Fitting the appliance cover

WARNING Electrocution
f Reconnect the earth cable to the appliance cover. f
f Place the cover back on the appliance. f
f Press the cover into the bead around the casing ring. f
f Connect the cable linking the programming unit to the PCB f
inside the appliance at the back of the programming/control
cover.
f Insert the programming/control cover. f
f Use the screw to secure the programming/control cover at f
the top of the appliance.
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