CTC Union EcoZenith i550 Pro Manual

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Installation and Maintenance Manual
CTC EcoZenith i 550 Pro
162 105 47-5 2016-04-07
IMPORTANT
READ CAREFULLY BEFORE USE
KEEP FOR FUTURE REFERENCE

162 105 47-5 2016-04-07
Installation and Maintenance Manual
CTC EcoZenith i 550 Pro

4
CTC EcoZenith i550 Pro
General Information
No liability is accepted for any misprints. We reserve the right to make design changes.
Quick reference
Fill in the information below. It may come in useful if anything should happen.
Product: Manufacturing number:
Installer: Name:
Date: Tel. no.:
Electrical installer: Name:
Date: Tel. no.:
Table of Contents
GENERAL INFORMATION 4
Check list ____________________________________________________________________ 6
Important to remember!_____________________________________________ 7
Safety Instructions _____________________________________________________ 7
Scope of delivery________________________________________________________ 8
1. CTC EcoZenith i550 Pro design _________________________ 9
1.1 Main components____________________________________________ 9
2. CTC EcoZenith i550 Pro function _____________________ 10
2.1 Heating System_____________________________________________ 11
2.2 DHW ___________________________________________________________ 12
2.3 Heat pump ___________________________________________________ 13
2.4 Wood Boiler__________________________________________________ 16
2.5 Additional boiler (pellets, oil, gas, electricity) _______ 17
2.6 Solar Energy _________________________________________________ 18
2.7 Recharging Bedrock/Ground ___________________________ 19
2.8 External Hot Water Tank _________________________________ 20
2.9 Pool ____________________________________________________________ 20
2.10 External Buffer Tank _______________________________________ 21
2.11 Cooling CTC EcoComfort________________________________ 23
3. The House Heating Curve _________________________________ 24
4. DHW ___________________________________________________________________ 28
5. Technical data____________________________________________________ 30
6. Measurements ___________________________________________________ 31
7. Menu overview___________________________________________________ 33
7.1 Room temp. _________________________________________________ 34
7.2 DHW ___________________________________________________________ 34
7.3 Operation _____________________________________________________ 35
7.4 Installer (Time/Language – Settings)__________________ 36
7.5 Installer – Define system _________________________________ 38
7.6 Installer – Service___________________________________________ 40
8. Detail Description Menus__________________________________ 42
8.1 Start menu ___________________________________________________ 42
8.2 Room temp. _________________________________________________ 43
8.3 DHW ___________________________________________________________ 45
8.4 Operation _____________________________________________________ 46
8.5 Installer ________________________________________________________ 54
9. Parameter list_____________________________________________________ 88
9.1 Define system _______________________________________________ 89
10. Operation and Maintenance______________________________ 90
11. Troubleshooting/measures________________________________ 92
11.1 Information messages ____________________________________ 94
11.2 Alarm messages____________________________________________ 95
FOR THE INSTALLER 97
12. Transportation, unpacking and installation ______ 97
12.1 Transportation ______________________________________________ 97
12.2 Unpacking____________________________________________________ 97
12.3 Fitting rear insulation and plastic top cover_________ 97
13. Parts list _____________________________________________________________ 99
14. Schematic diagram__________________________________________ 100
15. Pipe installation _______________________________________________ 102
16. Electrical installation _______________________________________ 113
16.1 Positioning of electrical components________________114
16.2 Safety switch _______________________________________________115
16.3 Heat pump power supply_______________________________115
16.4 Communication between the EcoZenith and CTC
EcoAir/CTC EcoPart______________________________________115
16.5 Low voltage 230V /400V (Heavy current) __________115
16.6 Sensor (Safety Extra-Low Voltage (SELV)) _________124
16.7 Current sensor connection _____________________________128
16.8 Settings made by the installation electrician.______129
16.9 Installing a backup power supply_____________________129
17. Installation of optional immersion heater_______ 130
18. Installation of additional boiler________________________ 131
19. Wiring diagram main card 3x400V__________________ 132
20. Wiring diagram main card 1x230V__________________ 134
21. Wiring diagram for expansion card ________________ 136
22. Parts list Wiring diagram_________________________________ 137
23. Resistances for sensors__________________________________ 138
24. First start__________________________________________________________ 139
24.1 Before first start____________________________________________139
24.2 First start_____________________________________________________140
25. Declaration of conformity________________________________ 142

5CTC EcoZenith i550 Pro
General Information
You have just bought a CTC EcoZenith i550 Pro, which
we hope you will be very pleased with. In the following
pages you can read about how to operate and maintain
your product. One part contains general information
and one part has been written for the installer. Keep
this manual containing the installation and maintenance
instructions. You will be able to enjoy the benefits
of your EcoZenith for many years, and this manual
provides all the information you will need.
The Complete System
The CTC EcoZenith i550 Pro is a complete system
which meets your home’s heating and hot water
requirements. It is equipped with a unique control
system that monitors and controls your entire heating
system regardless of how you choose to tailor it.
The CTC EcoZenith i550 Pro has a control
system that:
• monitors all hot water and heating system
functions;
• monitors and controls your heat pump, solar
panels, additional heat, buffer tank, pool, etc.;
• allows for individual settings;
• indicates desired values, for instance,
temperatures and energy consumption;
• facilitates settings in a simple and structured
manner.
Congratulations on buying your new product
Your CTC EcoZenith i550 Pro has built-in finned copper
coils which provide plenty of hot water and another
finned copper coil to handle the heat from solar panels.
The product also has a so-called cellar heat feature
during the summer and a floor feature which maximizes
the primary flow temperature.
Using the integrated night reduction function, you can
set and change the temperature in the property during
a 24-hour period, day by day, in blocks or as a vacation
function.
Service-friendly
Easily accessible electrical components, along with
effective troubleshooting functions in the control
program, make the EcoZenith easy to service. It is
supplied with a room sensor as standard, which is
equipped with LED lights that flash in the event of a
fault.
The EcoZenith is fully designed to work with the CTC
EcoAir 400 series outdoor air heat pump, the CTC
EcoPart 400 series bedrock/ground source heat pump,
CTCEcoAir510M230V1N~ och CTCEcoAir520M,
solar panels, water-jacketed stove and an additional
boiler where present. The EcoZenith can control a
number of combinations and provide you with an
extremely flexible, eco-friendly and energy-saving
heating system.

6
CTC EcoZenith i550 Pro
General Information
Check list
The check list must be completed by the installer.
• In the event of a service, this information may be called for.
• Installation must always be done according to the installation and maintenance instructions.
• Installation must always be carried out in a professional manner.
• Following installation, the unit should be inspected and checked for functionality.
Following installation, the unit must be inspected and functional checks performed
as indicated below:
Pipe installation
EcoZenith filled, positioned and adjusted in the correct manner according to the instructions.
EcoZenith positioned so that it can be serviced.
Capacity of the charge/radiator pump (depending on type of system) for the flow required.
Open radiator valves and other relevant valves.
Tightness test.
Bleed the system.
Safety valve function test.
The waste pipe is connected to the draining gutter.
Electrical installation
Compressor, direction of rotation (if heat pump installed).
Power switch
Correct tight wiring
Requisite sensors for applicable system
Outdoor sensor
Room sensor (optional)
Accessories
Information for the customer (adapted to current installation)
Start-up with customer/installer.
Menus/controls for selected system
Installation and maintenance manual supplied to the customer
Checks and filling, heating system
Trimming information, heat curve
Alarm information
Mixing valve
Safety valve function test
Warranty conditions
The installation certificate has been completed and posted.
Information on procedures for fault registration
______________________________________ ______________________________________
Date / Customer Date / Installer

7
CTC EcoZenith i550 Pro
General Information
Important to remember!
Check the following points in particular at the time of delivery and installation:
• The CTC EcoZenith i550 Pro must be transported and stored in an upright position.
When moving the product, it can be placed temporarily on its back.
• Remove the packaging and check before installation that the product has not been
damaged in transit. Report any transport damage to the carrier.
• Place the CTC EcoZenith i550 Pro on a solid foundation, preferably made of concrete.
If the product needs to be placed on a soft carpet, base plates must be placed under
the adjustable feet.
• Remember to leave a service area of at least 1 m in front of the product. Space is also
needed around the product for installation of insulation and plastic top cover. See the
chapter on Transportation, unpacking and installation in the section for the installer. The
CTC EcoZenith i550 Pro must not be lowered beneath floor level.
• Check for missing parts.
• The product must not be installed where the ambient temperature is higher than 60°C.
• CTCEcoAir510M230V1N must have Software HP PCB 20160401 or later.
• CTCEcoAir520M400V3N must have Software HP PCB 20160401 or later.
Safety Instructions
The following safety instructions must be observed when handling, installing and using the
product:
• All installation must be carried out by a qualified person in accordance with applicable
regulations.
• The product is only intended for vertical installation.
• Close the safety switch before doing any work on the product.
• Do not soak the product with water or any other liquid.
• When handling the product with a hoist ring or similar device, make sure that the lifting
equipment, eyebolts etc. are not damaged. Never stand under the hoisted product.
• Never jeopardize safety by removing bolted covers, hoods or similar.
• Never jeopardize safety by deactivating safety equipment.
• Any work on the product should be done by authorised personnel only.
• Safety valve check:
– The safety valve for the boiler/system and hot tap water must be checked on a
regular basis. See the chapter on Operation and maintenance.
This appliance is not intended for use by persons ( including children ) with reduced physical,
sensory or mental capabilities, or lack of experience and knowledge, unless they have been
given supervision or instruction concerning use of the appliance by a person responsible for
their safety.
Children should be supervised to ensure that they do not play with the appliance.

8CTC EcoZenith i550 Pro
General Information
Scope of delivery
Standard delivery
• Multitank CTC EcoZenith i550 Pro
• Additional package with:
–Installation and Maintenance Manual
–Outdoor sensor
–Room sensor
–Safety valve 9 bar (tap water)
–Safety valve 2.5 bar (radiator system)
–Drainage valve
–Adapter between the drainage valve and the connection sleeve
–Sensor, 2 off (to and from pipes)
–Current sensor, 3 off
–Cover washer for connections, upper and lower tank, 8 off
–Cover washer for solar coil connections, 2 off
–Insulation for connection sleeves that are not used
–Sensor labelling
–Screw 4.2 x 14 graphite grey, 25 off + 2 extra
–Screw 4.2 x 14 zinc grey, 4 off + 2 extra
• Additional package with rear insulation sections and plastic top

9CTC EcoZenith i550 Pro
General Information
1. CTC EcoZenith i550 Pro design
This chapter illustrates the main components and describes the subsystems
which, in different configurations, form part of the main system. For
more information about the EcoZenith configurations, refer to the “Pipe
connections” chapter.
1.1 Main components
more information about the EcoZenith configurations, refer to the “Pipe
connections” chapter.
1.1
Main components
Control System
The EcoZenith is equipped with
an intelligent control system which
controls and monitors all parts of
the heating system. The EcoZ-
enith ensures that the most eco-
nomical way of heating the house
and the hot water is prioritised.
Finned Coil for Hot Water
The EcoZenith is equipped with a
well dimensioned finned copper
coil and does not contain any
heater which can rust. A low
temperature can be maintained
without the risk of legionella
bacteria.
Immersion heaters in Upper
Part of Tank
Built-in upper immersion heater.
When connected to a heat pump,
the immersion heater acts as ad-
ditional heat.
(The uppermost immersion heater
is an accessory).
Lower tank
In the lower part of the tank, hot
water is preheated in the coil by
the solar- or heat pump-heated
water.
Solar Coil Connections
The well dimensioned, 10 m long,
finned coil can be connected
directly to the solar panels.
Lower immersion heater
Built-in lower immersion heater.
Upper Tank Connections
The upper part of the tank, the
additional part, can be heated by
heat pump and connected to heat
sources such as electric, gas, oil
and pellet boilers. Heat from a wood
boiler is delivered to this part. Con-
nections are placed symmetrically
on both sides of the tank.
Insulation
The tank is insulated by 90-mm-
thick molded polyurethane foam
for minimum heat loss.
Lower Tank Connections
The heat pump and solar system
are connected to the lower tank.
Water to be heated by wood boiler
is taken from here, and heat which
is to be stored in a buffer tank is
also taken from this part. Connec-
tions are placed symmetrically on
both sides of the tank.
Insulated tank divider
Between the tank’s upper and
lower tank is an insulated tank
divider. This provides high tem-
peratures in the upper tank for
good hot water capacity and low
temperatures in the lower tank for
best operating economy.
Heat Distribution Pipes
The heat distribution pipes ensure
that heat from the solar coil is di-
rected to the upper tank and that,
after hot water is drawn off, cooled
water is directed to the lower part
of the tank to be heated again by
solar energy or heat pump.
Upper tank
In the upper part of the tank, the
warm water in the coil is heated
up to the desired temperature.
Bivalent Mixing Valve
The automated mixing valve
ensures that an even heat is
continuously supplied to the radia-
tor system. The valve has double
ports and takes the warm radiator
water from the solar and heat
pump heated water in the lower
part of the tank first.
Fresh Water Connections
The property’s fresh water supply
is connected here. The cold water
is fed down to the lower part of
the coiling, where it is preheated.
Top Connection
For connection of expansion ves-
sel and/or safety valve.

10
CTC EcoZenith i550 Pro
General Information
upper tanklower tank
The CTC EcoZenith i550 Pro is a multi-tank with almost
unlimited possibilities.
The EcoZenith is intended for houses and properties with water-borne
heat. The multi-tank features include intelligent control, a water volume
of 540 litres, bivalent mixing valve, two hot water coils, a solar coil and
two 9 kW immersion heaters giving a total of 18 kW. You can easily add
another immersion heater as an accessory to provide total power of 27 kW,
controlled by the EcoZenith.
The control is specially adapted to simultaneously control up to three of
CTC’s heat pumps, but it will also control and optimise the following:
• Pool
• Energy storage in buffer tanks
• Three heating circuits simultaneously
• Solar panels and bore hole recharging
• Cooling (passive cooling), floor or fan convector
• Hot water circulation with time control
• Charging of extra domestic hot water tank
• Connected wood boiler, gas/oil boiler and pellets
The CTC EcoZenith is well-insulated with 90 mm PUR and is well provided
with connection options on both sides, ensuring clean and easy pipe
installations. It also provides for extensions and additions to the system in
the future.
The CTC EcoZenith i550 Pro is divided into two tanks which are isolated
from each other in order to be able to hold different temperatures in the two
tanks. This provides for optimal function and operating economy.
The upper and the lower tanks are connected by heat distribution pipes
which are especially developed for the solar energy to be able to form layers
optimally in the entire volume of the tank and act as flow-through of the tank
on wood operation, for instance. See figure.
See also Immersion heaters Menu in the Detail Description Menus
chapter (“Installer/Settings/Electric heaters”)
See also Lower tank Menu in the Detail Description Menus chapter:
“Installer/Settings/Lower tank”
2. CTC EcoZenith i550 Pro function
!Remember that
menus which
have not been
defined cannot be
seen.

11
CTC EcoZenith i550 Pro
General Information
2.1 Heating System
The EcoZenith is equipped with a bivalent mixing valve, which always
delivers an even temperature, without variation, to the heating system. The
bivalent mixing valve is controlled by an outdoor sensor and, optionally, by a
room sensor.
When operating with outdoor sensor alone, the desired curve inclination and
adjustment are set. These values differ from home to home and should be
adjusted to suit your needs.
A room sensor that is correctly positioned provides more comfort and
more heating system savings. The room sensor picks up the current indoor
temperature and adjusts the heat, for example when it is windy outside and
the house is losing heat, which the outdoor sensor is unable to register.
During solar insolation, or other instances when heat builds inside the house,
the room sensor can also reduce the heat, thus saving energy. Another way
to save energy is to use the night reduction function, which reduces the
indoor house temperature at certain times or periods, for example during the
night or when you are away on holiday.
The EcoZenith can control up to three heating systems, each with its own
room sensor. For instance, one radiator circuit plus two floor heating circuits.
The bivalent mixing valve always attempts to use the energy from the lower
tank first; this is especially important when a heat pump or solar panel
is connected to the EcoZenith. This ensures the system delivers good
operating economy and that the upper tank stays warm to provide an
abundance of hot water.
See also Heating system Menu in the Detail Description Menus
chapter (Installer/Settings/Heating circuit 1-3).
See also Room temperature Menu in the Detail Description Menus
chapter. You access the menu directly from the main menu.

12
CTC EcoZenith i550 Pro
General Information
2.2 DHW
The final heating of the hot water takes place in the upper tank. It also acts
as additional heating for the heating system when the lower tank is not
sufficient.
The hot water is heated using two finned copper tube coils of approx. 40
metres connected in parallel. The coils preheat the water in the lower tank
and the water reaches maximum temperature in the upper tank. The low
inner volume and high rate of water turnover in the copper coil prevents
build-up of bacteria.
With double coils, high draw-off flows can be obtained, as the heat
conduction area is finned, on the inside as well as the outside. For more
information on settings and tips, please see the DHW chapter.
2.2.1 Hot Water Circulation
The hot water coil has a connection for hot water charging, which can be
used to heat an external cold water tank when greater tap capacity of DHW
is required, and allows connection of hot water circulation. This means that
hot water is always available at the tap. To save energy the HWC pump can
be time controlled from the EcoZenith.
See also Upper tank Menu in the Detail Description Menus chapter
(Installer/Settings/Upper tank).

13CTC EcoZenith i550 Pro
General Information
upper tank
lower tank
port 1
port 2
2.3 Heat pump
The EcoZenith is designed with two parts in order to ensure the heat pump
operates to maximum possible economy.
The heat pump is connected via two diverting valves to the EcoZenith and
ensures that the heat is directed into the upper and lower tanks, respectively.
For instance, when the heat pump pumps towards the upper tank, the
diverting valves send the flow to the two uppermost connections, so that the
flow enters port 1 and exits through port 2.
The heat pump operates in two different ways, depending on whether it is
the upper tank or the lower tank being charged.
2.3.1 Upper tank
The final hot water heating takes place in the upper tank. This means that,
with a high upper tank temperature, an ample hot water supply is obtained.
The upper tank has a factory-set stop temperature of 55°C, which means
that the heat pump will work to achieve this temperature in the upper tank.
When hot water is being drawn off and the temperature in the upper tank
falls to 5°C below the stop temperature, the heat pump starts up and raises
the temperature towards the set stop temperature.
The stop temperature can be adapted to hot water needs and to the heat
pump model installed.
When there is also a need for heat in the house, the diverting valves will
automatically reverse direction and the heat pump continues to heat the
lower tank as soon as the stop temperature 55°C in the upper tank has
been reached. If the upper tank has not reached the stop temperature 55°C
within the factory-set 20 minutes of charging, the diverting valves reverse the
direction and the heat pump charges the lower tank. This is to prevent loss
of temperature in the heating system.
See also Upper tank Menu in the Detail Description Menus chapter
(Installer/Settings/Upper tank)
Pressure/level switch
In some cases, extra protection is required due to local requirements or
provisions. For example, the requirement in some areas is for the system
to be installed within a water catchment area. The pressure/level switch
is connected to blocks K22/K23/K24/K25 and then defined under the
Advanced/Define system/Def Heat pump menu. If there is a leak, the
compressor and brine pump stop and the Flow/level switch alarm appears
on the display.

14
CTC EcoZenith i550 Pro
General Information
2.3.2 Lower tank
In the lower tank the heat pump operates to provide heat to the heating
system.
Heat pump operation is of so-called floating condensation type. However,
the lower tank never drops below the set lowest temperature.
Floating condensation operation is where the heat pump heats to the
temperature required by the heating system. This temperature varies
depending on the outdoor temperature and which set inclination and
adjustment (the heat curve for the house) has been chosen. If a room sensor
is installed, this will affect the temperature required in the system. During
spring and autumn, when it is not so cold outside, a lower temperature is
needed for the heating system, but during winter a higher temperature is
needed to maintain the desired indoor temperature.
Savings from a heat pump are directly linked to the COP value. COP means
the output divided by the supplied power. COP 4 therefore means, for
instance, that the heat pump delivers 4 kW and uses 1 kW ( )
The lower the temperature the heat pump needs to deliver, the higher the
COP value obtained from the heat pump, as this will involve the compressor
working to better advantage.
Therefore, the heat pump heats only to the lower tank temperature the
heating system requires. This saves compressor life and maximizes operating
economy. The immersion heater, which is factory installed in the lower tank,
is blocked as long as the heat pump is operating.
The immersion heater is only brought into use if the heat pump is blocked for
any reason.
See also Lower tank Menu in the Detail Description Menus chapter
(Installer/Settings/Lower tank) and the DHW chapter.
4
1= 4
2.3.3 More Than One Heat Pump.
If more than one heat pump is installed, heat pumps two and three are
connected to the lower tank only.
Only one of the heat pumps alternates between DHW and heating operation.
2.3.4 Prioritisation of heat pump operation
When the CTC EcoLogic controls two or more heat pumps of different sizes,
the connected heat pumps are divided into two different categories: small or
large heat pumps. Dividing the available heat pumps into two different size
categories means it is possible to change the output in small steps and in
this way achieve modulating operation.
When, for example, a need for power occurs, a large heat pump is switched
on at the same time as a small heat pump is switched off, and vice versa
when reducing power. Within both the small and large groups reciprocal heat
pump operation is prioritised according to accumulated operation time.
When there is a mixture of different types of heat pumps, air/water and
bedrock/ground source pumps are prioritised according to current outdoor
temperature.
8 kW 12
kW
17
kW
17
kW
8 kW 12
kW
17
kW
17
kW
17
kW
17
kW
In the example above, 8 kW and 12
kW are classed as small, while the two
17kW machines are classed as large.
In the example above, 8 kW and 12
kW are classed as small, while the four
17kW machines are classed as large.

15CTC EcoZenith i550 Pro
General Information
2.3.5 Different Heat Pumps
The EcoZenith can control different types of heat pumps, the CTC EcoAir
(outdoor air heat pump) and the CTC EcoPart (bedrock/ground source
heat pump). The desired outdoor temperature at which the CTC EcoAir is
prioritised over the CTC EcoPart is set in the “Installer/Settings/Heat pumps
1, 2, 3” menu under “Prio EcoAir/EcoPart”. This means that the operating
economy can be maximised, as at a high outdoor temperature a greater
energy yield is obtained from the CTC EcoAir than from the CTC EcoPart.
This combination is excellent in installations where, for example, bedrock/
ground source heat pumps are designed with too much focus on “saving”
etc. An air/water heat pump may then be used to allow the bedrock more
time to “recover” and to provide increased output of the installation.
Remember that only one heat pump can be connected via the diverting
valves and charge hot water in the upper tank.
See also Heat pump Menu in the Detail Description Menus chapter
(Installer/Settings/Heat pump A1-A3)

16
CTC EcoZenith i550 Pro
General Information
2.3.6 Speed-controlled charge pump (accessory)
Each heat pump should be provided with a separate charge pump that is
controlled in tandem with its respective heat pump. If a speed-controlled
PVM charge pump (accessory from CTC) is connected to the heat pump
and controlled from the EcoZenith, the flow will be automatically set without
any adjustment needed via the control valve. In the upper tank the speed of
the charge pump will be controlled so that the heat pump always delivers its
highest possible temperature into the top of the EcoZenith. This provides for
quick access to hot water when the heat pump starts.
Towards the lower tank the speed-controlled charge pump will work for a fixed
difference between flow and return from the heat pump.
If a speed-controlled charge pump is not installed, the flow has to be adjusted
manually, and the difference between incoming and outgoing water from the
heat pump will vary, depending on the operation conditions during the year.
In cases where an air/water heat pump is installed and the outdoor
temperature is less than +2°C, the charge pumps are started in order to
protect against frost. If a speed-controlled charge pump is installed, the pump
will only work at 25% of its maximum capacity. This provides for increased
savings on the charge pump’s operating economy, and the heat losses in the
EcoZenith are reduced compared to a conventional on/off charge pump.
See also Heat pump Menu in the Detail Description Menus chapter (Installer/
Settings/Heat pump A1-A3)
2.4 Wood Boiler
The EcoZenith can be connected to a wood boiler.The primary flow from the
wood boiler is connected to the top of the EcoZenith and the return flow to
the wood boiler is connected to the lowest connection on the lower tank.
When firing is started and the flue gas sensor and/or boiler sensor reaches
a set value (menu “Installer/Settings/Wood boiler” factory-set “100/70°C”),
the control goes into wood operation status when the temperature of the
lower tank is above or equal to its reference value (setpoint). When the flue
gas sensor is below the set value, wood operation status is interrupted. It is
recommended the wood boiler be provided with a charge system. A charge
system such as Laddomat 21 is recommended for optimum performance. The
charge pump in the charge system must be controlled from the wood boiler.
In special cases, such as operation with a water-jacketed stove, the charge
pump may be controlled from the EcoZenith without installing a charge system
See also Wood Boiler Menu in the Detail Description Menus chapter
(Installer/ Settings/Wood boiler)

17CTC EcoZenith i550 Pro
General Information
2.5 Additional boiler (pellets, oil, gas,
electricity)
The EcoZenith can control an external additional boiler (pellets, oil, gas,
electricity). The additional boiler is connected to the upper tank. Use the
menu to select whether the external additional boiler should have high or low
priority. If high priority is selected, the external additional boiler is activated
before the immersion heater(s); when low priority is selected, the immersion
heater(s) is/are activated first.
After a certain delay, which is factory set at 120 minutes, the unit with low
priority is also started and helps the heat source with high priority.
If the immersion heaters are the lowest prioritised additional heat, the
following must also be fulfilled in order for them to start: The temperature in
the upper tank must be 4°C below the setpoint for the additional heat.
If the external boiler is the lowest prioritised additional heat, the following
must also be fulfilled in order for it to start: The temperature in the upper tank
must be 3°C below the setpoint for the additional heat and the immersion
heaters must have moved along to the desired value (100% of set value) or
to 6 kW in the first two hours after a power failure.
The EcoZenith handles start and stop of the charge pump between the
external boiler and the EcoZenith.
The charge pump starts when there is a need for an external boiler.
If a temperature sensor is installed and an extra boiler is defined, the charge
pump starts when an external boiler has reached the set temperature
(factory set at 30°C).
The charge pump stops when there is no need for an external boiler. A stop
delay of the charge pump can be set so that the charge pump runs even if
the external boiler is turned off
See also External Boiler Menu in the Detail Description Menus chapter
(Installer/Settings/Ext boiler)

18 CTC EcoZenith i550 Pro
General Information
illustration 2
illustration 1
2.6 Solar Energy
The EcoZenith contains a 10 m long 18 mm finned and internally grooved
solar coil which manages approx. 10 m² of solar panel. On larger solar panel
installations, the solar energy is connected via an external heat exchanger
(see figure 2). The heat exchanger is connected to the upper and lower
connections on the lower part of the CTC EcoZenith (either side is possible).
If a greater number of panels is connected, one or more buffer tanks can
also be installed in the system. More information on function and control of
buffer tanks can be found in the Extra Buffer Tank section.
If the solar panels produce a temperature which is more than 7 degrees
(factory-set) higher that the sensor (B33), the charge pump starts and
transfers the solar energy to the lower tank. The speed-controlled PWM
pump controls the flow so that it always delivers a temperature which is
7°C higher. This means that if solar panel output rises, the charge pump will
increase the flow, and if solar panel output decreases, the charge pump will
reduce the flow. When the temperature in the lower tank increases or the
solar panel loses temperature, and the difference between the temperature in
the solar panel and the lower tank is below 3 degrees (adjustable), charging
stops. Charging will not restart until the solar panel is again 7 degrees
warmer than the lower tank.
When the temperature in the lower tank rises and becomes warmer than
the upper tank, by the laws of physics, heat will rise into the heat distribution
pipe and layer itself into the right temperature level in the upper tank
through perforated holes in the distribution pipes. The colder temperature
in the upper tank will, in the same way, sink down and distribute itself in
its temperature zone in the lower tank through the distribution pipe which
descends into the lower tank. Based on the factory setting, the sun will heat
the lower tank in the EcoZenith to 85°C before the charging is stopped.
See also Solar Panels Menu in the Detail Description Menus chapter
(Installer/Settings/Solar panels)

19CTC EcoZenith i550 Pro
General Information
2.7 Recharging Bedrock/Ground
If a liquid-water heat pump is connected, a diverting valve can be installed
on the solar circuit and connected to the brine circuit (the loop in the bore
hole or the ground heat loop). The solar panel temperature should be
factory set at 60°C warmer than the brine temperature in order for charging
to start. When the difference between the temperature in the solar panel
and the brine circuit falls to 30°C, charging is stopped. If the brine circuit
becomes warmer than the factory-set value of 18°C, recharging will also be
interrupted, as the temperature then becomes too high for the heat pump to
work.
Safety measures for the collector/solar system are available.
See also Protection Collector Menu in the Detail Description Menus
chapter (“Installer/Settings/Solar panels/Protection collector”) and also
Winter Mode Menu in the Detail Description Menus chapter (“Installer/
Settings/Solar panels/Winter mode”)

20 CTC EcoZenith i550 Pro
General Information
2.8 External Hot Water Tank
An external water heater can be connected to the EcoZenith. This results
in a greater stored hot water volume, which contributes to higher hot water
capacity.
The incoming cold water first passes through the
EcoZenith where it is heated before it flows into the hot water tank and out
to the property’s taps. This means that, when the temperature from the
EcoZenith is no longer sufficient, the entire volume of the hot water tank is
still there to be used.
When the temperature in the upper tank of the EcoZenith is factory set 5°C
warmer than in the external hot water tank, the charge pump starts. The
heat from the upper tank charges the hot water tank until the increase in
temperature in the latter does not exceed one degree per three minutes.
When hot water is stored below 60°C, heating of the hot water tank at
regular intervals is necessary to eliminate the risk of Legionella. This function
is built into the EcoZenith. First the upper tank is heated as far as possible
using the heat pump. For the water heater to reach 65°C during 1 hour, the
immersion heater is allowed to engage to raise the temperature over the final
degrees. The factory setting for this is every fourteen days.
See also Upper tank Menu in the Detail Description Menus chapter
(Installer/Settings/Upper tank)
2.9 Pool
A pool is connected to the EcoZenith’s lower tank. Between the EcoZenith and
the pool, a heat exchanger is installed to separate the liquids.
A sensor in the pool starts and stops the pool’s charge pumps in order
to maintain the set temperature in the pool (factory set at 22°C), and the
temperature is allowed to fall by one degree before the charge pump
starts again. It is also possible to set the pool priority to high or low, which
determines whether or not additional heat can be used for heating the pool.
See also Pool Menu in the Detail Description Menus chapter (Installer/
Settings/Pool)