Thermona THERM EL 5 User manual

Operation and
Maintenance
Manual for
Electric Boilers
(user manual)
version: July, 2010
THERM EL 5
THERM EL 9
THERM EL 14
THERM EL 8
THERM EL 15
THERM EL 23
THERM EL 30
THERM EL 38
THERM EL 45

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1. CONTENTS
1. CONTENTS .................................................................................................................................................................2
2. GENERAL USE...........................................................................................................................................................3
3. GENERAL CHARACTERISTICS OF THERM – EL ELECTRIC BOILERS....................................................3
4. TECHNICAL DATA...................................................................................................................................................7
5. BASIC INSTRUCTIONS FOR BOILER INSTALLATION ..................................................................................8
6. BOILER OPERATION – LED DISPLAY WITH BUTTONS..............................................................................13
7. BOILER CONTROL AND DISPLAY OF BASIC OPERATIONAL INFORMATION....................................17
8. USER MENU – LED DISPLAY WITH BUTTONS..............................................................................................19
9. BOILER OPERATION – GRAPHIC TOUCH DISPLAY....................................................................................22
10. USER MENU – TOUCH DISPLAY ........................................................................................................................30
11. SPECIAL BOILER FUNCTIONS...........................................................................................................................34
12. HIDDEN BUTTONS ON THE TOUCH DISPLAY...............................................................................................34
13. PUTTING THE BOILER INTO OPERATION.....................................................................................................35
14. DIAGRAM FOR SERVICEABLE CONNECTING CHARGE PRESSURES OF HEATING WATER .........37
15. THERM EL BOILERS CONNECTION TO THE POWER SUPPLY ................................................................38
16. WARRANTY AND RESPONSIBILITY FOR DEFECTS ....................................................................................46
17. CONNECTION WITH SOLAR SYSTEM .............................................................................................................46
18. DOMESTIC HOT WATER STORAGE TANK HEATING MODE....................................................................47
19. THERM EL 8, 15, 23 (KW) BOILER ASSEMBLY..............................................................................................49
20. THERM EL 5, 9, 14 (KW) BOILER ASSEMBLY.................................................................................................50
21. THERM EL 30, 38, 45 BOILER ASSEMBLY (KW).............................................................................................51
22. WALL-MOUNTING OF THE BOILER ................................................................................................................52
23. BOILER DIMENSIONS AND CONNECTION .....................................................................................................53
24. RECORD OF REPAIRS AND ANNUAL INSPECTIONS ...................................................................................54

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2. GENERAL USE
The construction of THERM-EL electric boilers is designed for hot-water heating systems with induced water
circulation. They can be installed in central or individual-storey heating with induced circulation sealed or open
systems and they are characterized by an environmentally friendly operation without requirements for venting of
the combustion product. Service-free operation enables the installation of an external regulator, other external
regulating or controlling components (not included in the boiler delivery package!), simple equitherm regulator or
room thermostat integrated directly in the automatic controlling system which maintains the pre-set room
temperature. The electric boiler can be used as a universal source of heat for heating flats, small family houses,
resort houses and also as an alternative source to another main heat source of heating and hot water preparation
(also for transitional periods) – for heat pumps, accumulation systems or in previously installed central or single-
storey heating systems etc. To attain higher output levels, boilers can be connected into a cascade format.
3. GENERAL CHARACTERISTICS OF THERM – EL ELECTRIC BOILERS
Therm-EL electric boilers are wall-mounted appliances designed for water heating in a heating system and
potentially for domestic hot water heating (hereinafter referred to as “DHW”) in an indirect heating storage tank.
THERM EL boilers are produced in three series. The first, lower output series, has three types: 8, 15 and 23 kW ,
in the second higher output series there are a further 3 types: 30, 38 and 45 kW . In terms of the construction and
manner they are controlled and regulated in the same manner as with the output lower series. The latest series are
with touch display boilers in variants 5, 9 and 14 kW .
The electric boiler is formed by a steel vessel with inbuilt heating bars, heating temperature probe and safety
thermostat (these components are all located under one cover in the upper part of the vessel). The vessel is made
from a varnished steel sheet and it is fitted with thermal insulation. Heating water inlet, on which a circular pump is
mounted, is welded at the bottom part of the boiler. A lug located in the upper part of the vessel is adjusted to the
cup for the boiler temperature sensor and emergency thermostat. Heating water outlet and threaded sleeve pieces
are also located in the upper part of the vessel. Heating bars (up to 6) are screwed in the sleeve pieces. In variants
5, 9 and 14 kW there are 3 bars with the output 1.5 kW (each bar has three independent 0.5 kW heating bodies ), 3
kW (each bar has three independent 1 kW heating bodies ) and 4.5 kW (each bar has three independent 1.5 kW
heating bodies ), the remaining series of boilers have bars, each with the total output of 7.5 kW (in each heating bar
there are three independent heating bodies, each 2.5 kW). An automatic vent valve is placed at the highest point of
the water heating circuit.The boiler control box enables connection of an external room thermostat, addition of
interface for the boiler cascade connection type, programmable (time) switch and MRC (mass remote control) tariff
switch. Switching and electric line protection of the boiler and output inlets for the heating bars are not
located in the boiler but they always form part of the electric distributor of the flat or house. Terminals of the main
wiring are concentrated in the right part of the boiler. A sufficiently rated output line contactor or switch (correctly
marked!) which are used for disconnecting the electric boiler from the power network must be connected right next
to the boiler during its installation.
♦ Boiler operation characteristics:
Operational stage of the boiler is launched when heating system temperature drops below the temperature set
on the boiler control panel or on the room thermostat. Control circuit of the heating bars becomes activated and
heating water inside the boiler body becomes heated gradually. After the required temperature has been reached in
the room (if a room thermostat is applied), the control microprocessor unit starts switching off the heating bodies
one by one and the heating of the water stops. At this moment the function of an adjustable limited pump
deceleration (in terms of time or temperature) becomes activated.
As standard, Therm-EL boilers are also fitted with emergency thermostat which delivers maximum safety. It is
connected to the control circuit of the integrated output contactor. The disconnection of the emergency thermostat
(disjunction of the controlling circuit relay and heating bars) and thus the boiler shut-down occur when the
temperature reaches 105°C. Shall the emergency thermostat become disconnected, the boiler can be only put back
into operation by an authorized service engineer. Another protection of the boiler is assured by a pressure switch

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which disengages the control circuit when the heating system water pressure decreases (when there is not enough
water in the heating system). When the system becomes replenished with water, the boiler automatically relaunches
operation. Proper deaeration of the heating system must be assured prior to launching and also during boiler
operation. The heating system bleeding is partially ensured by the automatic vent valve which is placed at the outlet
of heating water from the boiler body.
♦ Selected important characteristics and merits of THERM- EL electric boilers:
• top microprocessor control
• digital 3-character LED display (displays selected temperatures, pressure, output, error and other messages) or touch LCD
display (displays alpha-numeric selected temperatures, pressure, output, error and other messages)
• very quiet operation (switch power relay of the heating bodies)
• state-of-the-art design
• ergonomic, interactive control
• fluent regulation by 0.5 kW (EL 5), 1 kW (EL 9), 1.5 kW (EL 14) and 2.5 kW for lower output series EL 8, 15, 23 (5 kW for
upper output series – EL 30, 38 and 45)
• service-adjustable pump deceleration
• protection of the pump against particulate build-up
• PID regulation
• anti-freeze protection
• DHW heating option (terminals for an external three-way valve, NTC temperature sensor or a storage tank thermostat)
• optional connection of an external NTC sensor (integrated equitherm regulation)
• connection of an NTC temperature room sensor (automatic controlling system as a room regulator)
• integrated safety switch contactor for all output phases
• possibility of an intelligent cascade boiler connection format (up to 32 boilers – with smooth output modulation)
• optional external control by means of GSM (external modem necessary)
• optional connection of an external regulator with OpenTherm communication
• balanced loading of the heating bars and bodies
• power relays do not form part of the processor board printed circuits (easy servicing and replacement). Special relays with
integrated fastons were used, i.e. high currents do not flow through printed circuits.
• boiler start system functioning on the basis of a mass remote control (MRC)
• external control of energy input (relief relay)
• soft start
• integrated Grundfos UPS 15/60 pump
• integrated 7 l expansion vessel (with the lower performance series)
• integrated safety valve
• automatic bleeding
• digital heating water pressure sensor (fitted with all types)
• auto-diagnostics, unequivocal service notification of defects
• optional boiler parameter adjustment (rich service menu)
• three-digit display (displays selected temperatures, pressure, output, error messages etc.)
• further 7 LEDs for unequivocal signalling of the operational conditions
• option of a default setting (immediate change of operation into the factory settings mode)

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♦ 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. Boilers EL 5, 9 and 14 are
equipped in standard manner with a touch display with easy-to-orientate control and signalling in various world languages.
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. The module is not included in the delivery. The module cooperates with the automatic system of the
REK electric boiler with software 6.0 and later. For later SW the function may slightly differ from this description.
It is not possible to combine with cascade connection of boilers !
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 control

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enables the boiler to operate in a low tariff rate and thus significantly reduce energy costs. Maximum boiler output can be
limited in the service menu if the operation must proceed also outside the so-called “low tariff”.
!!! Shall other ways of installing the MRC receiver be applied the output of which is one of the phases (MRC/L1 -
L3), it is necessary to assure transmission to the R level (reset conductor) by means of e.g. installing an auxiliary
relay in the external distributor.
Soft start
The soft start function rests in a gradual heat-up of the heating system which is therefore protected against abrupt upward
temperature gradient. When the boiler is switched on or a new regulation period is initiated and the resulting quick change in
temperature caused by induction of heat into the system could also bring about noise due to the dilatation of pipes, the boiler is
actuated in the so-called “soft start” and limits the output after it is launched.
Auto-diagnostics, unambiguous signalling and service messages
THERM-EL electric boilers are equipped with a very useful system of auto-diagnostics chiefly with respect to service. This
function facilitates speedy and efficient removal of a potential boiler defect. Apart from the commonly displayed user values –
heating water temperature (the TOP circuit), DHW temperature, outdoor or room temperature sensor, TOP circuit pressure –
the display can show other service information if the service menu is set up correspondingly: E.g. disconnection or short circuit
of all sensors, boiler output, MRC condition and other error messages.
Wide choice of parameter settings
Service and user menus of THERM-EL boilers provide a wide range of boiler settings according to specific conditions of
operation or based on customer requirements:
- The option of setting various outputs for the heating water and heating of DHW undoubtedly offers positive financial effects.
- The possibility of setting different outputs with the MRC signal switched on or off provides the user with a pleasant heat
comfort.
External energy input control
If there are several concurrently operating electrical apparatuses and the household has increased requirements for power take-
off, the THERM-EL boiler user will certainly appreciate the external energy input control function. A relief relay can be
connected to the distributor with a pre-set value of the electric current. If the current reaches e.g. 30 A, the boiler disconnects a
specified number of heating bars and relieves the whole system.
SLEEP standby mode
Another function the advantage of which will be namely appreciated by those users who stay outside home for longer periods
of time is the SLEEP mode. This mode is used in situations when the house will not be inhabited for an extended period and
the user wants to have the heating system reliably safeguarded against solidification or freeze-up. Boiler in the SLEEP mode
consumes minimum amount of power but the protective boiler functions – spinning, unblocking and anti-freeze protections –
are also active. If the boiler is connected to an equitherm sensor, the drop in outside temperature activates an anti-freeze
protection which can protect not only the actual boiler but the entire heating system.
If during the boiler's operation none of the control panel buttons becomes activated, the display automatically
switches over to the saving mode (only the LED is turned on).

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4. TECHNICAL DATA
Lower performance series:
THERM
EL 5
THERM
EL 9
THERM
EL 14
THERM
EL 8
THERM
EL 15
THERM
EL 23
Nominal th
ermal output
kW
4,5
9 13,5 7,5 15 22,5
Minimum regulating
output
level
W
500 1000 1500 2500
2500 2500
Number of output regulation
-
9 9 9 3 6 9
Rated current
A
7(21) 13(39) 20(60) 11(33) 22(66) 33
Level of electrical coverage
IP
40
40
Electric
ity
voltage / frequency
V/Hz
3 x 400/230 + N + PE/50 3 x 400 + N + PE/50
Max. rated current A
3 x 8 (1x24)
3 x 14
(1x42) 3 x 21 (1x63)
3x 12
(1x36)
3 x 24
(1x72) 3 x 36
Main
electricity
circuit breaker
A
10(25A) 16 (50) 25 (80) 16 (40) 25 (80) 40
Nominal current for the control
A
1,25
1,25
Electrical service life of relay
-
1.10
5
cyklů(16 A, 250V/50 Hz)
Mechanical service life of relay
-
10.106 cyklů
Input
–
output of heating water
-
G 3/4" vnější
Minimum working over
-
pressure
bar
0,8
Maximum working overpressure
bar
2,5
Maximum temperature of the
°C
80
Water volume of the boiler
1
6,0
14,5
14,5
Efficiency at nominal output
%
99
99
Volume of expansion tank
1
7
7
Maximum number of boilers in
ks
32
32
Dimensions (heigh
t/ width /depth)
mm
625/475/235
805/475/235
805/475/235
Weight of the boiler without water
(gross)
kg
27 (30) 27 (30) 27 (30) 37 (40) 38 (41) 39 (42)
Higher performance series:
THERM EL 30 THERM EL 38 THERM EL 45
Nominal heat output kW 30 37.5 45
Rated current A 44 55 66
El. components degree of shielding IP 40
Power voltage / frequency
V/Hz
3 x 230 + N + PE/50
Max. rated current A 3 x 48 3 x 60 3 x 72
Wiring main circuit breaker A 50 A 63 A 80 A
Rated current of the control system fuse
A 1.25
Electric durability of the relay - 1.10
5
cycles (16 A. 250V/50 Hz)
Mechanical durability of the relay - 10.10
6
cycles
Heating water inlet/outlet - male G 1"
Min. service overpressure of the
heating assembly bar 0.8
Max. service overpressure of the
heating assembly bar 2.5
Max. heating water temperature °C 80
Boiler water capacity 1 28.0
Effectiveness for nominal output % 99
Expansion vessel capacity l to order (placed outside the boiler!)
Max. number of boilers in the cascade pcs 32
Dimensions (height/ width /depth) mm 805/475/235
Boiler weight without water kg 56.5 59.5 62.2

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♦ Manufacturing control
All boiler parts are checked and correctly set by the manufacturer prior to final assembly. Each boiler is tested
on water circuit tightness and the function of the regulating and safety components is set and tested as well.
The boiler was manufactured in line with:
Standards: CSN EN 60 335-1, CSN EN 60 335-2-30, CSN 06 1008, CSN 07 7401, CSN 06 0810, CSN 07
0240, CSN 06 0310, CSN EN 60 730, CSN 06 0830, CSN EN 60 730-1, CSN 06 1010; Government Regulations:
No. 163/2002 Coll., 17/2003 Coll. and 18/2003 Coll.
5. BASIC INSTRUCTIONS FOR BOILER INSTALLATION
Electric boilers are designed for permanent connection to a fixed mains supply voltage. A disconnecting device
– main circuit breaker and a corresponding electric line protection – must be installed in the permanent electric
boiler mains.
Installation of electric boilers can be carried out only by a qualified expert company or authorized worker with
the required qualification level in the field of electrical equipment maintenance. In the process of installation, all
pieces of advice as well as warnings included in this Manual must be observed. It must be performed in compliance
with the valid standards and provisions! The connection of an electric heating is subject to authorization issued by
the local power distribution plant. An applicant must ask for a provisional approval with the connection of a higher
energy input and for a relevant direct heating dwelling unit tariff. In the case of construction of a new or repair of
an old central heating system, we suggest that the design is elaborated by an expert. Performance of an expert
installation by an authorized service organization is always the precondition for warranty provision by the
manufacturer! Connection to the electric network and the wiring can be carried out only by an expert worker
qualified in line with the Czech Decree No. 50/1978 Coll.
Installation location must be chosen for the electric boiler which will enable necessary access for the operator or
for the purposes of a service inspection. Minimum distances between the boiler and a solid obstacle are shown in
the Figure in the Chapter “Wall-mounting of a boiler”. Ask an expert worker of the company which performs the
installation for a demonstration of the system function and training for operation. Once the boiler has been put into
operation, a letter of guarantee must be certified by the authorized expert service worker.
In the location of the electric boiler installation pressure water for filling the heating system and water discharge
point must be available. It is further necessary that the room has a sufficiently even wall (electric boiler is wall-
mounted).
♦ Boiler location
Electric boilers can be installed in the basic environment
AA5/AB5 according to the standards CSN 2000-3 and CSN
33-2000-5:51 (range of temperatures between +5 and 40°C,
humidity depending on the temperature of maximum 85 %, no
harmful chemical influences). It can be installed in residential
as well as non-residential spaces with the exception of rooms
with a bathtub or shower, in bathrooms and wash rooms in
general in zones 1 and 2 according to CSN 33 2000-7-701. It
cannot be however installed in zone 3 in locations where a
water jet designed for cleaning can form. If the boiler is
installed in the permitted zones, relevant electric current
accident protection must be concurrently performed in
accordance with the same standard, too.
The installation location must be chosen which will allow sufficient access for the operator as well as service
inspector.
Degree of shielding of the boiler electric components is IP 40.

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♦ Wall-mounting of the boiler
Electric boiler is mounted on the wall by means of a
fixing strip (1) supplied with the boiler according to the
Figure in the Chapter “Wall-mounting of the boiler”. If the
boiler is mounted on a wall with a lower carrying capacity, it
is recommended to consult the installation with a civil
engineering technician. Free space of at least 200 mm below
and 750 mm above the lower and upper edges of the
jacketing shall be left for the purposes of inspecting the
boiler or replacing the heating bodies (see Figure depicting
the boiler wall-mounting and installation).
♦ Connecting the boiler to the hot-water heating system
Electric boiler must be connected to the distribution network in a manner preventing its aeration. Connection to
the heating system must be tackled in a project design calculating hydraulic ratios of the whole system because the
installation involves a hot-water flow-through boiler fitted with an integrated pump. It needs be noted that
minimum flow through the boiler must be constantly assured for the designated boiler output at maximum thermal
gradient of the heating system amounting to 20°C. Any reduction of this flow (due to integrated high hydraulic
friction elements) results in insufficient circulation and drop in life-time of some boiler parts. To utilize the
maximum output of the heat exchangers, ensure correct functioning and high durability, the minimum heating
system overpressure must amount to 0.8 bar.
Proper rinsing of the heating system resulting in the removal of all impurities must be performed prior to testing
and launching the operation of the whole system in line with CSN 06 0310 within the framework of the installation.
A suitable filter must be unconditionally fitted in the recuperative water inlet from the heating system into the
boiler to prevent impurities from entering the boiler system.
The heating system must be installed in accordance with CSN 06 0830 -- Safety equipment for central heating
and domestic hot water heating and CSN 06 0310 – Central heating – designing and assembly.
Shall the boiler be connected to a sealed heating system, such system must have a pressure expansion vessel of
sufficient capacity (higher performance series boilers are not equipped with their own expansion vessel).
!!! We recommend:
 fill the system with soft water in line with CSN 07 7401;
 fit the boiler outlet with a bleeding device;
 mount a filter or a sludge device into the pump suction section;
 overflow valve should be installed in heating systems with thermostatic valves
 mount a heating system charge and discharge cock and a sludge cock at the lowest point of the system in
the very proximity of the electric boiler
 separate all electric boiler types on inlet and outlet by stop valves, too (see standards CSN 06 8030), not to
be forced to discharge the whole system in case of inspection or repair of the boiler or during filter
replacement
 remove control levers from stop valves and secure them against manipulation.
♦ Boiler connection to electric network
Wiring can be installed only by an authorized person in the sense of the Decree No. 50/1978 Coll. on
professional qualification in electrical engineering. Certification of the boiler installation and putting into operation

10
must be noted in a proper manner on the letter of guarantee. Any interference with internal boiler wiring (with the
exception of wiring specified in this Manual, e.g. the external regulator connection instead of jumper wire) are
inadmissible!
The boiler control box must be connected according to the relevant CSN standard by means of a
separately protected line which enables its disconnection and which is located in the very proximity of the
electric boiler!
Current protective switch must be used if the electric boiler is installed in a bathroom.
The power wiring is connected by a 5-conductor system to the U, V, W, N and PE terminals. In the case of a 4-
conductor system the N and PE terminals shall be connected together and the power wiring matched with the U, V,
W and PE terminals.
If MRC is connected to the boiler control box, the MRC receiver outlet is matched with the terminal marked
HDO/N.
1
WARNING! When using the MRC receiver signal on the HDO/N terminal, it must be made sure that all
contactor coils of other appliances (e.g. of the boiler if it is connected to the common MRC signal) are energized
with the same phase!
When operation must be delivered also outside the so-called “low tariff”, the maximum boiler output
limit can be switched off in the service menu also without the MRC signal (P4.4)!
Recommended cable cross sections under the plaster:
Boiler output [kW] 5 9 8 14 15 23 30 38 45
Power take-off [A] 7 13 12 20 24 36 48 60 72
PVC insulated cable with copper
conductors 5 [sq.mm] 2,5 2,5 2,5 4 4 6 10 16 25
♦ Connection of electric boilers to one phase
Therm EL 5, EL 9, EL 14, EL 8 and EL 15 electric boilers can only be connected in certain cases to a single-
phase distribution line.
Connection of Therm EL 5, EL 8, EL 9 and EL 14 electric boilers to a single phase distribution system.
For the connection of EL 5, 8, 9 and 14 boilers, a connection unit is delivered which connects all three
terminals. The supply cable with cross-section max. 10 mm
2
(for EL 14 max. 16 mm
2)
can be connected to any of
the three terminals marked L1, L2 or L3. We recommend to protect using a single-phase circuit breaker according
to the table!
The connecting strip with bolts is attached to the boiler. Before the connection it is necessary to remove the
plastic separating partition pieces between the individual phase terminals.
1HDO is the Czech abbreviation for MRC: translator's note.
3
phases jumper

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Connection of the Therm EL 15 electric boiler to a single-phase distribution line.
For the connection of boiler EL 15 to a single-phase set of terminals a DIN bar is delivered which is
screwed into the prepared holes in the metal sheet under the existing terminals and for the prepared conductors it is
connected to the original terminals. This ensures the connection of all three-phase distribution lines inside the
boiler and the possibility to connect the supply cable with the conductor with a cross section of a max.16 mm
2
. We
recommend protecting using a single-phase 80A circuit breaker! The connecting set has the storage number 43473
– “Set for connection to 1 phase for EL 15”.
♦ Charging the heating system
For the duration of the heating system charging, the boiler must be unplugged from the electric network by
disconnecting it by the main circuit breaker. It is useful to maintain the level of filling pressure in a cold system in
the range between 1 and 1.5 bar. Filling must proceed slowly in order to let the air bubbles escape through the
respective valves. According to CSN 07 7401 the water used for the first filling as well as for refilling must be
clear, colourless, without any suspended substances, oil or chemically aggressive admixtures, with a minimum
carbonate hardness (max. 3.5 mval/l) and it cannot be acidic (pH cannot be below 7). Only approved agents can be
used for water hardness adjustments.
Non-observance of the aforementioned requirements results in cancellation of the undertaking for the
damaged components!
♦ Choice of the regulating and controlling components
The boiler is fitted with basic regulatory and safety elements as the following electric diagrams show. Therm-
EL boilers can regulate their outputs. They are equipped with their own PID regulation which does not allow
heating over the set temperature. Even if the TOP temperature is set to 80°C, electric boilers frequently overheat up
to the temperature of 96°C, while THERM-EL boiler heats up to the maximum temperature of 84°C.
It is always suitable and economical to let the electric boiler be controlled by a superior regulatory element
(room thermostat or an OpenTherm communication regulator). These regulators are not included in the boiler
delivery package!
Connection of a room thermostat and servicing of the boiler electric section may be carried out only by
authorized service organizations!
Regulation based on temperature in a referential room (room regulator) or an equitherm regulation of the
heating water, or potentially both, can be used as further extensions to the regulatory option. A whole series of
regulatory or switch thermostats can be used to control the room temperature: E.g. PT 10, PT 21, PT 30, BPT 30,
PT 30 GSM, REV 23, CM 707, CM 907 or OpenTherm communication regulators such as CR 04, PT59, Therm
RC 03 or Siemens QAA 73.110.

12
Regulators (room regulator, water temperature thermostat, trip relay of the current value monitor or an
OpenTherm regulator) can be connected to the boiler's input terminals (24V= circuits).
Current value monitor HJ 103T is a device used for disconnecting or reducing the output of the electric boiler
when other high power input electrical appliances (e.g. flow-through water heater, washing machine, dish-washer,
stove etc.) are connected to the network. Such a device is rules out the necessity of purchasing a high-capacity main
circuit-breaker which also means the payment of a high lump fee.
If a part of the electric boiler needs to be disconnected, the tripping device becomes connected to the terminals
for a trip relay (see the wiring scheme). The output size which becomes disconnected by individual trip relays is set
by changing the parameters ( P0¯ , P1¯ , P2¯ , P3¯ ) in the control panel (from zero to maximum) in the service
menu.
If the contact of the external tripping device should disconnect the whole boiler, it shall be either connected
serially in combination with the room thermostat (24V=) or to the terminals of the blocking element (230V/50Hz).
Equitherm (outside temperature) regulation
Heating water temperature in the equitherm regulation system is controlled on the basis of outdoor temperature.
The regulation takes place according to equitherm curves which specify the dependence between outdoor
temperature and the temperature of heating water required to reach the desired room temperature. An equitherm
curve must be drawn on the basis of designed, calculated or measured heat losses of the building. This type of
regulation does not have any feedback which would take into account higher cooling on one side of the house by
wind or heating by sun and, as a result, it cannot safeguard accurate temperature regulation in all parts of the house.
Boiler connection to room thermostat and Therm Q01 outdoor sensor enables utilizing the equitherm regulation
which leads to additional energetic cost-cutting. THERM EL boiler is moreover capable of cooperating with
OpenTherm communication interface regulators without any further communication interface installation. The
inclination and shifting of equitherm curves can be modified in the automatic control user menu .
Regulation according to room of reference
Used in family houses. Only temperature of a selected room is monitored on the basis of which the entire
flat environment is regulated. Other rooms with diverse heat losses will be heated to different temperature unless
further thermoregulating knobs are not installed on the radiators. This method has the advantage of a more flexible
regulation. If an NTC temperature sensor located in the room of reference is connected to the boiler automatic
control system – without any other external regulator – the automatic control system can be used as a simple room
regulator (adjustable in the user menu – a Prt heating mode).
Cascade connection of boilers
The cascade connection format means connecting the boilers by means of technical elements into one set
the task of which is common heating of large spaces in a manner which complies with requirements for a desired
Heating water temperature [°C]
Outdoor temperature [°C]

13
heat comfort. Boilers can be arranged in a cascade (see wiring diagrams) by way of a simple interface which
divides the actual electronics from the surrounding environment. Boiler electronics enable connecting up to 32
boilers in one single intelligent cascade which will modulate the output ranging from the minimum performance of
the first boiler to the sum of maximum outputs of all boilers.
REKAS 1 interface (not included in the delivery package!) needs to be installed in both master and slave boilers.
The master boiler is in addition fitted with a master regulator (selection of the master and slave boiler is done in the
service menu).
♦ MRC – mass remote control
Mass remote control (MRC) enables transmission of electricity as well as various commands to the users
regarding tariff switching on the electrometer and operation of some appliances via standard distribution network.
Mass remote control is a set of technical means (e.g. emitters, receivers, central automatics, transmission routes
etc.) serving the emission of commands or signals for switching on or off electrical appliances. The MRC system
has replaced the switch clock used in the past. Each customer who makes use of tariff switching must be equipped
with a respective device which ensures this activity. This device is placed on the electrometer panel and cooperates
with the electric boiler. The MRC receiver is an apparatus which performs the required switching operation (it for
example blocks or unblocks an electrical appliance) as a result of a processed MRC signal.
Depending on the service setting, the boiler can be operated either only if the cheaper tariff signal is activated (the
“HDO” LED is turned on) or if the user requires so (Ph¯ parameter, P4.4).
6. BOILER OPERATION – LED DISPLAY WITH BUTTONS
Description of the control panel:
Control panel is simple and intuitive and displays the boiler functions.
The panel uses colour-coding and graphical division of the heating and DHW preparation sections. LEDs
positioned between the buttons for setting the temperature higher/lower (up/down arrows) are turned on if the
particular mode is selected (i.e. either the DHW
2
preparation mode or the heating water mode marked TOP).
If the display shows any other variable, pressing one of the ▲ , ▼ buttons (1) displays the heating water
temperature (the LED “°C” TOP is turned on).
If the display shows any other variable, pressing one of the ▲ , ▼ buttons (2) displays the DHW temperature (the
LED “°C” DHW is turned on).
Changing the value of the desired variable: When the heating water temperature is displayed (the LED “°C”
TOP is on), the first pressing of one of the heating temperature setting buttons displays the setting for the required
value of this temperature. This is indicated by the flashing of LED “°C” TOP. Required value can be changed
within the ranges defined in the service menu. The set value becomes automatically registered in the memory after
15 seconds of inactivity (measured after the last button was pressed).
The required DHW temperature is set in a similar fashion (by the DHW temperature setting buttons).
The five LEDs below the main display show the variables which are currently set or indicated on the 3-digit
display:
- if the LED “ °C ” (TOP or DHW) is on, the display shows the temperature of water in the heating or DHW
circuits
- if the LED “
IN
/
OUT °
°°
° C ” is on, the display shows the temperature of the outdoor or room temperature sensors
- if the LED “ HDO ” is on, the MRC signal is activated and the boiler produces heat in the low tariff
- if the LED “ bar ” is on, the display shows the pressure in the TOP system in bars
2 The Czech abbreviation for DHW is TUV: translator's note.

14
Automatic control elements (user access):
1. Buttons for displaying heating temperature settings ▲ , ▼ (1) – higher/lower, additionally, if selected,
browsing through the service MENU
2. Buttons for displaying DHW temperature settings ▲ , ▼ (2) - higher/lower, the flashing value of the
selected variable can be also changed in the menu)
3. Heating on/off button O/I (MENU) (3) (press shortly) , open the MENU (press for more than 2 seconds) ,
exit the MENU (press shortly)
4. DHW heating on/off button O/I (ENTER) (4) (press shortly) , ENTER (press shortly only in the MENU)
5. SELECT – main display selection button (SELECT) (5):
• temperature (according to the menu and selected option)
• water pressure (bar)
• output (kW)
• error messages (last error)
• heating mode
6. 3-digit 7-segment LED display
7. 7 LED indicators for the selected functions
HDO bar
SELECT
°C
IN
OUT
(ENTER)
O/I
°C
O/I
(MENU)
°C
SELECT
(ENTER)
O/IO/I
(MENU)
HDO bar°C OUT °C
IN
°C
DHW temperature
setting
buttons
DHW
heating
on/off
Button for
the display mode
and mode
and parameters
settings
7x LED indication
for the selected
functions
Heating
temperature
setting
buttons
Heating
on/off
buttons
5
6
2
4
1
3
7
LED display

15
♦ Error indication
ERROR MESSAGES:
Error code Type of defect
E.00 NO DEFECT
E.01 reserve
E.02 LOW PRESSURE (detected by the analogue pressure sensor)
E.03 BLOCKING ELEMENT
E.04 HEATING WATER (TOP) NTC TEMPERATURE SENSOR DEFECT
E.05 DHW (TUV) NTC TEMPERATURE SENSOR DEFECT
E.06 EMERGENCY THERMOSTAT (manual reset directly on the thermostat!)
E.07 OUTDOOR/ROOM TEMPERATURE SENSOR DEFECT
E.08 reserve
E.09 PRESSURE SENSOR DEFECT – analogous pressure sensor
E.10 COMMUNICATION PROBLEM between boilers in the cascade – master boiler
E.11 COMMUNICATION PROBLEM between boilers in the cascade – slave boiler
- past defects register (1–20)
Apart from the E.06 defect (emergency thermostat temperature becomes exceeded), all other defects shut down the
boiler and bring it to the defect state (heating bars become disconnected) which is automatically revoked only after
the defect has been removed. The boiler's operation is then automatically re-initiated.
Defect detected by the emergency thermostat is irreversible (the thermostat is equipped with manual reset
function which can be used only by an authorized service worker after the defect has been properly detected
and addressed).
♦ Menu parameters
It can be always selected (in the user menu by the diS / P3.2 parameter) whether the item is displayed in the
numerical format (more suitable in foreign language versions of the automatic control system) or in the
mnemotechnical format (closer to the Czech language).
MENU PARAMETERS:
Mnemo
format
Numerical
format
USER MENU Initial
settings
Et1 P1.1 CURVE SLOPE AT BININ N.UTL = 0 (night moderation – disconnected) 1.6
Et2 P1.2 CURVE SHIFT 1 0
Et3 P1.3 CURVE SLOPE 2 AT BININ N.UTL = 1 (night moderation – connected) 1.6
Et4 P1.4 CURVE SHIFT 2 -5
ti1 P2.1 ROOM TEMPERATURE 1 AT BININ N.UTL = 0 (night moderation –
disconnected) for rto=Prt 21
ti2 P2.2 ROOM TEMPERATURE 2 AT BININ N.UTL = 1 (night moderation – connected
for rto=Prt 19
tdr P2.3 DIFFERENCE – REGULATORY RANGE (PROPORTIONAL) 3
tdf P2.4 DIFFERENCE – HYSTERESIS OFF/ON 0.5
GSE P6.6 ALLOW GSM MODEM AUTOMAT. SENDING ERROR SMS 0 (NE)
rto P3.1 HEATING OPERATION MODE (tEr,EtE,Prt,otP,ot-) tEr
diS P3.2 DISPLAY TYPE FOR THE MENU AbC

16
Mnemo
format
Numerical
format
SERVICE MENU
(opening this MENU is permitted only to the service engineer with the
authorization of the manufacturer!)
rtU P3.3 DHW (TUV) HEATING OPERATION MODE (temperature probe/thermostat)
to_ P3.4 LOWER LIMIT FOR THE HEATING WATER TEMPERATURE SETTING
to¯ P3.5 UPPER LIMIT FOR THE HEATING WATER TEMPERATURE SETTING
tU_ P3.6 LOWER LIMIT FOR THE DHW TEMPERATURE SETTING
tU¯ P3.7 UPPER LIMIT FOR DHW TEMPERATURE SETTING
FtL P3.8 BINARY INPUT FUNCTION
PSt P4.1 START OUTPUT
Pt¯ P4.2 MAX. OUTPUT DURING HEATING
PU¯ P4.3 MAX. OUTPUT DURING DHW HEATING
Ph¯ P4.4 MAX. OUTPUT WITHOUT MRC SIGNAL
P0¯ P4.5 MAX. OUTPUT AT DISCONNECTED CONTACTS OF RELIEF RELAY 1 AND 2
P1¯ P4.6 MAX. OUTPUT AT CONNECTED CONTACT OF RELIEF RELAY 1
P2¯ P4.7 MAX. OUTPUT AT CONNECTED CONTACT OF RELIEF RELAY 2
P3¯ P4.8 MAX. OUTPUT AT CONNECTED CONTACTS OF RELIEF RELAY 1 AND 2
tSt P5.1 LIMIT OF THE REQUIRED VALUE OF TOP HOT-WATER OUTLET (to start heating)
ttU P5.2 REQUIRED OUTLET TEMPERATURE DURING BOILER HEATING
bdF P5.3 DIFFERENCE BETWEEN DHW HEATING ON/OFF
C_T P5.4 TIME LIMIT FOR THE OUTPUT/TEMPERATURE AFTER HEATING START
dCt P5.5 PUMP DECELERATION TIME AFTER HEATING IS FINISHED
dCU P5.6 PUMP DECELERATION TIME AFTER DHW HEATING IS FINISHED
AF_ P5.7 SYSTEM ANTI-FREEZE PROTECTION
UP0 P5.8 PRESSURE SENSOR VOLTAGE AT P=0
UP4 P5.9 PRESSURE SENSOR VOLTAGE AT P=4
h.01-h.21 ERROR HISTORY DISPLAY
i.01-i.12 SERVICE AND DIAGNOSTIC INFORMATION
tYP P6.1 BOILER TYPE SETTING
Adr P6.2 MULTIPLE BOILER FORMAT (CASCADE) CONTROL PARAMETER
GSo P6.3 ENABLE COMMUNICATION WITH GSM MODULE
Pn1 P6.4 FIRST GROUP OF TWO DIGITS PIN FOR GSM MODULE
Pn2 P6.5 SECOND GROUP OF TWO DIGITS PIN FOR GSM MODULE
PARAMETERS SET FOR THE MASTER CASCADE BOILER
PCC P7.1 NUMBER OF BOILERS IN THE CASCADE
dCC P7.2 SYSTEM CASCADE PUMP DECELERATION
dC1 P7.3 BOILER PUMP DECELERATION, IN THE CASCADE, AFTER ITS HEATING
OPERATION IS FINISHED
AFC P7.4 CASCADE SYSTEM ANTI-FREEZE PROTECTION FREEZE
PhC P7.5 MAXIMUM CASCADE OUTPUT WITHOUT MRC SIGNAL
P0C P7.6 MAXIMUM CASCADE OUTPUT AT DISCONNECTED CONTACTS OF RELAY 1
AND 2
P1C P7.7 MAXIMUM CASCADE OUTPUT AT CONNECTED CONTACT OF RELAY 1
P2C P7.8 MAXIMUM CASCADE OUTPUT AT CONNECTED CONTACT OF RELAY 2
P3C P7.9 MAXIMUM CASCADE OUTPUT AT CONNECTED CONTACTS OF RELAY 1
AND 2

17
7. BOILER CONTROL AND DISPLAY OF BASIC OPERATIONAL INFORMATION
(more detailed user instructions)
♦ Heating water temperature display
After its connection to the power network, the display shows heating water temperature in °C which is
indicated by the pilot light °C above the O/I (MENU) button (3) . If any other variable is displayed at the moment
(DHW temperature, output, error message etc.), pressing any of the buttons ▲ , ▼ (1) opens the heating water
temperature dialogue.
In the case of sensor defect, the numerical data become replaced with dashes: _ _ _ during disconnection or interruption of the sensor or
wiring, ¯ ¯ ¯ after short circuit on the sensor or wiring.
♦ Displaying and changing (setting) the desired temperature of heating water
If you press any of the ▲ , ▼ buttons (1) with the display showing the heating water temperature dialogue, you
can display its desired value. Slow flashing of the °C pilot light above the O/I (MENU) button (3) shows the
desired value. The currently valid desired temperature value according to the operational mode is displayed (e.g.
calculated by means of the integrated equitherm regulator or integrated room thermostat by way of a
communication line from the external regulator).
If you press any of the ▲ , ▼ buttons (1) with the display showing the desired heating water temperature, you
can set the desired value. Faster flashing of the °C pilot light above button 3 indicates the setting process. The
desired temperature value can be set by means of ▲ , ▼ buttons (1) within the range defined by TO_ a TO¯ ( P3.4
a P3.5 ) items in the service menu. The set value does not need to be confirmed. The mode of setting the desired
value terminates 15 seconds after any of the ▲ , ▼ buttons were last pressed (1) .
The set desired value is valid in the following situations:
-rto heating mode is set to tEr (P3.1 = 1) (control performed by contact of the external room thermostat),
- rto heating mode is set to EtE (P3.1 = 2) (equitherm regulation) but the outdoor temperature sensor defect has been reported,
- rto heating mode is set to Prt (P3.1 = 3) (integrated room thermostat) but the room temperature sensor defect has been reported,
- rto heating mode is set to otP or ot- (P3.1 = 4 or 5) (external OpenTherm protocol regulation) but communication has failed.
♦ DHW temperature display
If any other variable is displayed at the moment (heating water temperature, output, error message etc.),
pressing any of the buttons 2 opens the DHW temperature dialogue. This display is indicated by the °C pilot light
above button 4 .
In the case of sensor defect or absence, the numerical data become replaced with dashes: _ _ _ during disconnection or interruption of the
sensor or wiring, ¯ ¯ ¯ after a short circuit on the sensor or wiring.
♦ Displaying and change (setting) of the desired DHW temperature value
If you press any of the ▲ , ▼ buttons (2) with the display showing the DHW temperature dialogue, you can set
its desired value. The setting process is indicated by flashing of the °C pilot control above the O/I (ENTER)
button (4) . You can set the desired temperature value by pressing the ▲ , ▼ button (2) within the range defined by
the TU_ a TU¯ ( P3.5 a P3.6 ) items of the service menu. The set value does not need to be confirmed. The setting
mode for the required values terminates 15 seconds after any of the ▲ , ▼ (2) buttons has been last pressed.
The desired DHW temperature value can be set only if the rtU DHW heating mode is set to b_c (P3.2 = 2) (storage tank with the temperature
sensor).

18
♦ Switching the heating on or off
The heating mode can be switched on or off by pressing the O/I (MENU) button (3) . The on-mode is
signalled by the pilot light between ▲ , ▼ buttons (1) ; the pilot light in the off-mode is turned off.
Heating can be switched on only if its operation is pre-set in the user menu; the rto item must be set to tEr, EtE, Prt, otP or ot- (P3.1 = 1 –
5).
♦ Switching the DHW heating on or off
The DHW heating mode can be switched on or off by pressing the O/I (ENTER) button (4) . The on-mode is
signalled by the pilot light between ▲ , ▼ buttons (2) ; the pilot light is off if the DHW is in the off-mode.
The DHW heating can be switched on only if its operation has been pre-set in the service menu; the rtU item must be set to b_n or b_c (P3.3
= 1 or 2).
♦ Displaying the outdoor/room temperatures
To display any other operational variables (except for the heating water and DHW temperatures), use the
(SELECT) button (5) . If you press (or double press) it, the outdoor/room temperature display dialogue opens.
This dialogue is indicated by the IN/OUT °C pilot light.
In the case of sensor defect or absence, the numerical data become replaced with dashes: _ _ _ during disconnection or interruption of the
sensor or wiring, ¯ ¯ ¯ during short circuit of the sensor or wiring
The difference between displaying the room or outdoor temperature rests only in the location of the sensor. Shall the boiler operation be
controlled on the basis of its data, the respective mode must be selected in the user menu:
- for rto = EtE (P3.1 = 2) (integrated equitherm regulation) outdoor sensor must be used,
- for rto = Prt (P3.1 = 3) (integrated room thermostat) sensor in the room of reference must be used.
If the sensor is connected but the boiler operation is not controlled on the basis of its data, these data are used at least for protecting the
system against freezing.
♦ Displaying the heating system pressure
If you press (or double press) the (SELECT) button (5) , the system pressure dialogue opens. This display
dialogue is indicated by the bar pilot light.
Minimum operation pressure of the system is 0.5 bar.
♦ Signal indication of the mass remote control (MRC)
The presence of the MRC signal is indicated by the HDO (MRC) pilot light. If it is turned on, it means that the
full boiler input is allowed.
Reduction of the boiler input by way of MRC signal can be set in the service menu by means of the Ph¯ (P4.4) item.
♦ Displaying the error messages
If you press (or double press) the (SELECT) button (5) , the error message dialogue opens. This display
dialogue is indicated by the letter E in the first position of the digital display. If an error message is generated, it is
displayed automatically. To display any other variable, press buttons 1, 2 and 5 .
If several simultaneous error messages occur, all of them are displayed (each for one roughly second): e.g.
E.02 – E.04 – E.05 – E.02 – E.04 – E.05 – ...
E.00 no defect
E.01
reserve
E.02 is low TOP water pressure in the heating system. Boiler operation is not possible in any mode.
Water pressure measured by analogous pressure sensor is below 0.5 bar.

19
E.03 is a disconnection of the blocking element 2 . Boiler operation is not possible in any mode.
E.04 is a defect on NTC sensor for the TOP heating water temperature. Boiler operation is not possible in any mode.
When the respective value is displayed, the lower dashes ( _ _ _ ) are displayed in the case of disconnection or
interruption of the sensor or its wiring, the upper dashes ( ¯ ¯ ¯ ) if there is a short circuit on the sensor or its
wiring.
E.05 is a defect of NTC sensor for DHW temperature . The boiler operation in the heating mode is possible,
DHW heating is not possible in the b_c (storage tank with sensor) mode and it is possible in the b_n (storage tank
with thermostat) mode. For further details see the rtU parameter for the operation of the DHW heating in the
service menu.
If the respective temperature setting is selected, lower dashes (_ _ _) are displayed if the sensor or wiring have been
disconnected or interrupted, upper dashes ( ¯ ¯ ¯ ) are displayed for short circuit on the sensor or wiring.
E.06 defect – emergency thermostat of TOP heating water temperature . Boiler operation is not possible (only after a
manual reset!).
E.07 is a defect of the NTC sensor for outdoor/room temperature . Boiler operation in the heating mode is
possible. If, however, the EtE heating mode (equitherm regulation) or Prt (integrated room thermostat) are
selected, the boiler automatically switches to the boiler thermostat mode (outlet water temperature control
according to a value set by buttons 1 ). DHW heating is possible in any of the modes.
If a respective display is selected, the lower dashes ( _ _ _ ) are displayed if the sensor or wiring have become
disconnected or interrupted, upper dashes ( ¯ ¯ ¯ ) stand for short circuit on the sensor or wiring.
E.08 reserve
E.09 is a defect of the TOP heating water pressure sensor – analogous sensor. Boiler operation is not possible in any of
the modes.
E.10 is a defect of the communication between boilers connected in a cascade which has been detected by the
master boiler . To display the details about this defect, press button 5. Addresses of all boilers are alternately
displayed (each for the time of approximately 1 second) which do not communicate with the master boiler:
E.10 – c.04 – c.05 – E.10 – c.04 – c.05 – ...
E.11 is a defect of communication between boilers connected in a cascade which has been detected by one of the
slave boilers .
♦ Displaying the instantaneous boiler output
If you press (or double press) the (SELECT) button (5) , the display dialogue of the instantaneous boiler output
opens. This dialogue is indicated by the letter P in the first position of the display. The output is shown in kW
( P.2.5 =2.5 kW, P.18 = 18 kW etc.).
8. USER MENU – LED DISPLAY WITH BUTTONS
♦ Accessing the user menu
To access the user menu, press the O/I (MENU) button (3) for more than 2 seconds. To move between the
menu items, press the ▲ , ▼ buttons (1) . If you want to change the input values, press the ▲ , ▼ buttons (2) . The
entered value in the menu must be confirmed by pressing the O/I (ENTER) button (4) . Exit the menu and data
input by pressing the O/I (MENU) button (3) .
The menu item (the set variable) and its value display alternately (e.g. Et1 – 1.6 – Et1 – 1.6 ...). The menu item
is displayed either by means of mnemotechnical texts
(Et1) or numerical parameters (P1.1) . The display mode is
set in the menu by way of the diS (P3.2) item.

20
♦ User menu items
Group 1: Integrated equitherm regulation parameters
Equitherm regulation defines the desired value of heating water temperature depending on the outdoor temperature.
The selection of parameters for the calculation depends on the specification of the binary NU (night moderation) .
If NU is disconnected, the following is true:
the desired heating water temperature value = (20 – outdoor temperature) * Et1 + 20 + ET2
If NU is connected, the following is true:
the desired value of heating water temperature = (20 – outdoor temperature) * Et3 + 20 + ET4
The desired outlet heating water temperature value is limited in the range between to_ (P3.3) and to¯ (P3.4) .
Equitherm regulation always requires the connection of an outdoor temperature sensor and the heating mode setting
of rto = EtE (P3.1=2) .
Et1 P1.1 Equitherm regulation parameter, curve slope . True for a disconnected NU .
The setting range falls between 0.1 .. 6.0, step of 0.1, leading value is 1.6.
Et2 P1.2 Equitherm regulation parameter, curve shift. True for a disconnected NU .
The setting range is -20°C .. +40°C, step of 1°C, leading value is 0.
Et3 P1.3 Equitherm regulation parameter, curve slope . True for a disconnected NU .
The setting range falls between 0.1 .. 6.0, step of 0.1, leading value is 1.6.
Et4 P1.4 Equitherm regulation parameter, curve shift . True for a connected NU .
The setting range falls between -20°C .. +40°C, step of 1°C, leading value is -5.
Group 2: Integrated room thermostat parameters
An integrated room thermostat can control heating operation according to the data from internal temperature
sensor. It uses proportional control to set the outlet water temperature within the range defined by the tdr (P2.3)
parameter:
- if TM < ti1 - tdr (TM < P2.1 – P2.3 ), heating is controlled to reach the maximum heating water temperature to¯
(P3.4) ,
- if TM > ti1 (TM > P2.1 ), heating is controlled to have the minimum heating water temperature to_ (P3.3) ,
- if ti1 - tdr < TM < ti1 ( P2.1 – P2.3 < TM < P2.1 ), the desired heating water temperature is calculated by the
interpolation between to_ and to¯ ( P3.3 a P3.4 ),
- if TM > ti1 + tdF , the heating is switched off completely.
The aforementioned is true if the NU binary input specification is “disconnected”. If the NU binary input
specification is “connected”, a value of ti2 (P2.2) is used instead of ti1 (P2.1) .
ti1 P2.1 Desired value of the room temperature. True if NM is “disconnected”.
The setting range falls between 10 and 30°C, step of 1°C, leading value is 21°C.