3
2.
USE
The THERM ELN boiler is a suspension hot-water electric boiler designed for heating hot water systems
with forced water circulation. The electric boiler can be used as a universal heat source for heating flats, family
and holiday homes as well as an alternative source when another main heating source is used, such as heat
pumps, accumulation systems, etc.
In addition to heating, the boiler can also be used to heat domestic hot water (DHW) in an external indirect
storage tank (so called DHW module needs to be added).
3.
GENERAL DESCRIPTION
THERM ELN boilers come with two output levels: 8 and 15 kW. The core of the electric boiler consists of
a steel vessel with integrated heating rods, heating temperature sensor and safety thermostat. The vessel is made
of coated sheet steel with thermal insulation. In the bottom part of the boiler vessel there are return water and
heating water outlets. The collar in the upper part of the vessel is adjusted for the temperature sensor pocket and
emergency thermostat sensor pocket. In the upper part of the vessel, there are threaded coupling sleeves. The
7.5 kW
heating rods
(1-2 pcs - in each heating rod, there are three separate 2.5 kW heating bodies) are bolted
to the coupling sleeves. The bottom part of the boiler features a special hydroblock which is fitted with a
circulation pump, by-pass, pressure sensor and heating system filling and discharge valves. At the highest point
in the boiler´s water circuit, there´s an automatic air vent valve.
The boiler is controlled and regulated by the automatic microprocessor control system which is situated in
the upper part of the boiler under the control panel, along with other electric components (contactor, main
wiring terminals).
The boiler
switch, circuit breaker and power lines for the heating rods, is not situated on the boiler,
but
is part of the el. switchboard for the given flat or house.
During installation of the electric boiler, there needs
to be sufficiently dimensioned main contactor or switch (properly marked!) connected in its immediate
vicinity
, which is used to disconnect the electric boiler from the mains.
♦
Description of the boiler operation:
The operating phase of the boiler is initiated when the temperature of the heating system drops under the
temperature set on the boiler control panel or under the temperature set on the room thermostat. The control
circuit of the heating rods is activated and the heating water in the boiler body is heated up gradually. When the
required room temperature is reached (when the room thermostat is used), the microprocessor control unit starts
disconnecting the heating bodies one by one and the heating water will no longer be heated. At this moment, the
adjustable pump rundown is activated.
In order to ensure maximum safety, the THERM ELN boiler comes with an emergency thermostat as
standard. The emergency thermostat is connected within the control circuit of the integrated electric contactor.
The emergency thermostat is disconnected, and thus the boiler is put out of operation (disconnection of the
control circuit of the relay and heating rods), once the temperature reaches 105°C. When the emergency
thermostat has been disconnected, only an authorized service technician may put the boiler back into operation.
Another safety feature of the boiler includes the pressure sensor which disconnects the control circuit if the
water pressure in the heating system decreases (a lack of water in the heating system). When water in the
heating system has been re-filled, the boiler is put back into operation automatically. Before the boiler is
switched on and while it is in operation, air needs to be bled properly out of the heating system. Air is bled out
of the heating system partly via the automatic air vent valves situated at the highest point of the boiler body and
on the pump.
