Guide book
Instantaneous water heater system WM 400 V
Page 11 from 17
5.5 Instantaneous water heater
The instantaneous water heater is completely electronically controlled and heats the
water as it flows. The electronic regulation and control unit detect the water flow, the inlet
temperature and the temperature selector at the specified outlet temperature. The
microprocessor calculates the required value and turns on the appropriate heat output.
When closing the hot water valve, the heater is turned off independently and the
electronic all poles system disconnected from the mains. The device consists essentially
of the heating block, the power module with triacs, the electronic module, a safety
temperature and pressure limiter and the pressure differential switch
.
Heating coils are used as a radiator, which are surrounded by flowing water directly. By
this heating mode and with 0.5 litres of very low water content, a high efficiency is
ensured. The amount of water is limited by a built-in flow control by fully open hot water
valve to max.10l / min flow rate so that a suitable outlet temperature for the shower
(about 40º C) remains.
Thanks to the built-in temperature and pressure safety limiter, a double safety shut-off is
reached by over pressure and over temperature. The pressure limiter triggers by a rise in
pressure
to about
22 bars, the temperature limiter triggers at about 55º C in the intake
and at about 70º C in hot-water outflow. In response of the pressure or temperature
limiter the device is disconnected at once from the mains.
Prior to press again the pushbutton on the safety temperature and pressure limiter,
the
cause of the disorder is to be determined and resolved by a qualified person
