Operation Manual

5
♦ Brief characteristics of the main merits of THERM-EL electric boilers:
Simple and intuitive operation
The control is designed in a simple, understandable and unambiguous way. Simple operation is also enabled by way of a
three-digit LED 7-seg display complemented by an unambiguous signalling system of a series of LEDs.
Pump protection against clogging
Regular spinning of the pump (once every 24 hours) prevents potential clogging of the pump during an extended boiler
down time.
Optional DHW heating
It is possible to additionally connect an external indirect DHW heating storage tank to the THERM-EL boiler. Heating of
the storage tank water is ensured by means of changing the position of the three-way valve. The boiler electronics can
communicate with the temperature sensor (continuous DHW temperature regulation) as well as with the traditional storage
tank thermostat (can be set in the service menu).
External regulatory elements
Boiler control by way of room thermostat or equitherm sensor is commonplace. Connection of the boiler to the room
thermostat or equitherm probe leads to further savings for electricity. The THERM-EL boiler is moreover able to cooperate
with regulators communicating via the OpenTherm communication protocol. Additional communication interface is not
necessary.
If the NTC temperature sensor is connected only in a room of reference according to which the whole heated space is
regulated, automatic control system can be used as a simple room regulator! (This can be set in the user menu.)
Safety switch contactor
Safety three-phase contactor is inserted in the power branch circuit at the boiler inlet which can cut the power from the
heating bars in case of emergencies and detected incorrect conditions (for further details see auto-diagnostics of the
automatic control system) and prevent a potentially dangerous situation from occurring.
Boiler cascade connection format option
The boiler electronics enable connection of up to 32 boilers into a single intelligent cascade which modulates the
performance ranging from minimum output of the first boiler to the total of maximum outputs of all boilers combined. The
interconnection of the master and slave boilers is possible only through a system of intelligent modules – i.e. the same
interface must be used for master as well as slave boilers.
GSM operated boiler
The boiler can be switched on and off by means of a mobile phone (it is however necessary that an external modem is
used; the modem is not an item of the boiler delivery package!). The boiler operation can be remotely launched by calling
on a GSM modem connected to the boiler, for example prior to returning from holiday, so that the house has a pleasant
temperature at the time of arrival.
Balanced service load of heating bars
Principle of a balanced service load on the heat bars extends their life-time. The heating bar which was connected first will
be also disconnected first within the framework of the regulation cycle which leads to an increase in overall reliability and
prolonged durability of the appliance. The processor assess the operational time of individual heating bars and actuates
them in a manner which ensures a thermally balanced loading of the boiler (the boiler body) and even service load of the
bars.
MRC system for launching the boiler operation
THERM-EL boilers signal and respond to commands from the MRC receiver of the external distributor. The output signal
of this receiver must be connected to the reset conductor which is attached to the MRC/R terminal. This method of remote