Id.Nr.: 229224-9 •
19
District heating tank FSN and FSN-E
19. Initial Commissioning
B F
Before switching on the electrical power the storage tank must be filled with water.
During the heating up process the expansion water generated in the inner boiler must drip out of the
safety valve in the case of a pressure resistant connection and out of the mixer unit in the case of a
non-pressure connection.
Caution: The initial heating up process must be carried out and monitored by a licensed pro-
fessional and The hot water drainage pipe as well as parts of the safety fittings can get hot.
After heating up the configured temperature and the actual temperature of the extracted water
should by about the same.
20. Decommissioning, Draining
B F
If a water heater is put out of action or not used for a lengthy period then it must be drained and
completely isolated (all-poles) from the power supply. Switch off the supply line switches or automatic
circuit breakers.
In rooms permanently subject to frost damage the water heater must be drained before the start of
the cold weather season if the device will be out of action for several days and is not being operating
in frost protection mode (see Point 6).
The draining of the domestic water is carried out once the shut-off valve has been closed in the cold
water feed via the drainage valve of the safety valve combination whilst all hot water valves of the
connected operating mechanisms are simultaneously open. It is also possible to drain the system via
the safety valve in the excess water funnel (drip tray). In order to do so the safety valve knob is turned
to the "Test" position.
Careful: hot water can escape when draining.
Furthermore when there is a risk of frost, attention must also be paid to the fact that not only the
water in the water heater and in the hot water plumbing can freeze but also in the all cold water pipe-
work to the operating mechanisms and to the device itself. It is therefore useful to drain off all water
carrying fittings and plumbing (including the heating circuit = smooth pipe heat exchanger) right back
to the frost protected part of the household water system (household water connection).
If the storage system is brought back into service then it is crucial to ensure that it is filled with water
and that bubble free water emerges at the hot water valves.
