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243648-1
Electric water heater EHT - 50, 80, 100, 120, 150 litres
14. INSPECTION, MAINTENANCE, SERVICE
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 connection).
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If the water heater is not heated up or hot water is withdrawn, no water must drip from the safety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) and observe the heating
process in the same way as during first commissioning.
c) In order to ensure a corrosion protection and be entitled to any claims for warranty, as provided
on the side of the manufacturer, the installed magnesium anode requires checking by an expert at
intervals of max. 2 years of operation (DIN 4753 Part 3). 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. In hospitals and other public buildings, the prevailing regulations for cleaning and
disinfection must be observed.
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.
15. MALFUNCTIONS
If the tank water is not heated, please check whether the line circuit breaker (automatic safety cutout)
or the safety fuse in the distribution box have reacted, and check the setting of the temperature
control.
In all other cases, do not attempt to rectify the fault yourself. Please contact either a licensed plumber
or our customer service. In many cases it only needs a little manipulation by an expert and the tank is
in order again. In case of contact, please quote your model designation and manufacturing number,
which you can find on the rating plate of your electric tank.
