15
Id.Nr.: 228843-13
Electric water heater EKA, EKR, EWH, EKL
13.2 Pressureless connection
By using fittings for pressureless connection (overflow mixer taps), it is also possible to
make a pressureless connection for a pressure resistant storage tank.
In the cold water supply line, no safety valve is required. However, a non-return valve, a
stop valve and a drain valve are required!
This type of connection is advantageous if only one hot water tapping point is needed.
The operation of the storage tank is effected at the fitting (mixer tap) by the hot water
valve – it acts as a shut-off element in the cold water inlet of the storage tank. This means
that the retrieval of hot water from the storage tank works as follows: by opening the
hot water valve, cold water is pushed into the storage tank from below, allowing the hot
water to exit freely through the upper hot water drain via the overflow mixer tap.
The fittings for pressureless connection are built in such a way that the hot water drain
always stays open, even if the hot and cold water valves are closed. Therefore, there is
always a connection between the storage tank and the outside air. The expansion water
produced by the heating procedure can flow out freely through the hot water drain.
Where required, the stop valve can be used to separate the storage tank from the cold
water supply network. The tank can now be drained through the drain valve.
