24
Id.Nr.: 231769-9
EHT 50 - 150
In the case of a risk of frost, it must be observed also that not only the water in the water heater and
in the hot water lines can freeze, but also in all cold water supply lines to the service fittings and to
the device itself. Therefore, it is advisable to empty all fittings and lines holding water (also heating cir-
cuit = bare tube heat exchanger) back to the frost-safe part of the domestic water system (domestic
water supply).
If the storage tank is put back into operation, then it must bindingly be observed that it is filled with
water
and water exits bubble-free at the hot water valves.
14. Inspection, Maintenance, Service
U E
a) During heating, the expansion water must drip visibly from the drain of the safety valve (the
expansion water drips from the valve of the mixing tap in the case of an unpressurised connec-
tion). The expansion water quantity is approx. 3.5% of the tank’s rated volume when fully heated
(approx. 80 °C).
The function of the safety valve must be checked regularly. The water must flow freely from the
safety valve unit into the drain funnel when the safety valve test knob is lifted or turned to the
“Test” position.
Caution: the cold water supply and parts of the storage tank connector fittings may become hot
thereby.
If the water heater is not heated up or hot water is withdrawn, no water must drip from the safety
valve. If this is the case, then either the water line pressure is too high (install pressure reducing
valve over 5.5 bar) or the safety valve defect. Please call a plumbing expert immediately!
b) The boiler scale as well as the furring forming in the internal boiler of the tank must be removed
by an expert after one to two years of operation in the case of heavily calciferous water.
Cleaning is performed through the flange opening. De-install heating flange, clean tank; a new
seal must be used in any case when the heating flange is mounted. The internal tank of the
water heater with special enamelling must not get in contact with boiler scale solvents – do not
use an anti-liming pump. Remove lime deposits with wood and aspirate or wipe out using a
cloth.
Then rinse the device thoroughly (in accordance with ÖNORM H5195-1) and observe the heating
process in the same way as during first commissioning.
c) In order to be entitled to any claims for warranty, as provided on the side of AE AG, the installed
reactive anode requires checking by an expert at intervals of max. 2 years of operation. The
guard circuit shunt resistor below the heating unit fastening screw must not be damaged or
removed during maintenance works.
d) Do not use any abrasive cleaning agents and paint thinners (such as nitro, trichlor etc.) to clean
the device.
The best cleaning method is to use a damp cloth added with a few drops of a liquid household
cleaner.
During maintenance works, it is advisable to open the cleaning and service flange in order to check
the tank for any possible washing-in of foreign objects and contaminations, and to remove these if
necessary.
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