13
Id.Nr.: 228843-13
Electric water heater EKA, EKR, EWH, EKL
13. Water connection
13.1 Pressure resistant connection
Any warranty for our water heaters is rendered null and void if unsuitable or non-func-
tioning storage tank connection fittings are used and if the stated operating pressure is
exceeded.
Water heaters whose rating plate states a nominal pressure of 6 bar (atü or kp/cm2) are
pressure resistant storage tanks. In this case, a closed connection with a line pressure
of up to 5.5 bar (atü) is permitted.
However, if the line pressure is higher, a pressure-
reducing valve must be fitted in the cold water supply line.
Use only tested diaphragm safety valves or a diaphragm safety valve combination - con-
nection fitting for pressure resistant storage tanks - for the water connection!
A safety valve combination consists of stop valve, test valve, non-return valve, drain valve
and safety valve with expansion water drain. It is fitted between the cold water supply line
and the cold water inlet (blue) of the storage tank in the indicated order.
As a general rule, the following should be observed:
A faultless function of the connection fitting can only be guaranteed if it is installed in a
frost-protected room. The drain of the safety valve must be open and observable. To
prevent disturbances and clogging due to frost or dirt and similar, do not lead the drain
line from the drip catcher (expansion water funnel) into the open.
Furthermore, the drainpipe of the safety valve must be installed with a continuous down-
ward inclination.
It is not permitted to fit stop valves or another reducer between the safety valve and the
cold water inlet of the storage tank.
The response pressure setting of the safety valve must be lower than the nominal pres-
sure (6 bar) of the storage tank. The discharge openings of the safety valves (domestic
water and heating circuits) must open out into an appropriate drainage object in order to
avoid any damage caused by the escape of operating fluid.
Before the final connection of the storage tank, the cold water supply line must be
flushed.
Once the water is connected and the storage tank is filled with (bubble-free) water, it is
necessary to check the function of the connection fitting.
